FRM17 v Minister for Home Affairs

KEY STATUTORY PROVISIONS 8 As we have indicated, the separate questions concern the application of s 494AB of the Migration Act (the bar) to all four proceedings before the Court. At all relevant times, s 494AB was in the following terms: 494AB Bar on certain legal proceedings relating to transitory persons (1) The following proceedings against the Commonwealth may not be instituted or continued in any court: (a) proceedings relating to the exercise of powers under section 198B; (b) proceedings relating to the status of a transitory person as an unlawful non-citizen during any part of the ineligibility period; (c) proceedings relating to the detention of a transitory person who is brought to Australia under section 198B, being a detention based on the status of the person as an unlawful non-citizen; (ca) proceedings relating to the performance or exercise of a function, duty or power under Subdivision B of Division 8 of Part 2 in relation to a transitory person; (d) proceedings relating to the removal of a transitory person from Australia under this Act. (2) This section has effect despite anything else in this Act or any other law. (3) Nothing in this section is intended to affect the jurisdiction of the High Court under section 75 of the Constitution. (4) In this section: Commonwealth includes: (a) an officer of the Commonwealth; and (b) any other person acting on behalf of the Commonwealth. ineligibility period means the period from the time when the transitory person was brought to Australia under section 198B until the time when the person next ceases to be an unlawful non-citizen. 9 The Commonwealth parties relied on ss 494AB(1)(a), (ca) and (d) in support of their contention that the bar applied to each of the four proceedings. 10 The expression "transitory person" is defined in s 5(1), relevantly for these proceedings, to mean: (a) a person who was taken to another country under repealed section 198A; or (aa) a person who was taken to a regional processing country under section 198AD; or … (d) the child of a transitory person mentioned in paragraph (aa) … if: (i) the child was born in a regional processing country to which the parent was taken as mentioned in the relevant paragraph; and (ii) the child was not an Australian citizen at the time of birth; or … There was no dispute that the applicants in all four proceedings were and are transitory persons, as defined in s 5(1) of the Migration Act. 11 Strictly speaking, the four cases here may be subject to different versions of the Migration Act, although nothing appears to turn on any differences in answering the separate questions. In extracting the key provisions in these reasons, we have used the compilation provided to us by both parties at the hearing. At the hearing, Mr Horan QC urged us to rely on the version that applied at the date of the hearing, including the provisions introduced by Home Affairs Legislation Amendment (Miscellaneous Measures) Act 2019 (Cth), assented to on 1 March 2019. We note that Mr Horan QC referred to these amendments in passing, but that no party developed any submission that they are important in resolving the separate questions. In contrast, the Commonwealth parties informed us that the compilation as at 9 December 2017 was "safe" to rely on, although Mr Howe QC stated that he was using the 12 August 2018 compilation. 12 Subdivision B of Div 8 of Pt 2 of the Migration Act (which is expressly referred to in s 494AB(1)(ca)) is headed "Regional processing". Section 198AA sets out the reason for this subdivision as follows: 198AA Reason for Subdivision This Subdivision is enacted because the Parliament considers that: (a) people smuggling, and its undesirable consequences including the resulting loss of life at sea, are major regional problems that need to be addressed; and (b) unauthorised maritime arrivals, including unauthorised maritime arrivals in respect of whom Australia has or may have protection obligations under the Refugees Convention as amended by the Refugees Protocol, should be able to be taken to any country designated to be a regional processing country; and (c) it is a matter for the Minister and Parliament to decide which countries should be designated as regional processing countries; and (d) the designation of a country to be a regional processing country need not be determined by reference to the international obligations or domestic law of that country. 13 Provision is made in this subdivision of the Migration Act for the Minister to designate a country as a regional processing country (under s 198AB), to which unauthorised maritime arrivals are to be taken (under s 198AD). Broadly speaking, under s 5AA(1), an unauthorised maritime arrival is a person who entered Australia by sea without a visa. Under s 5AA(1AA), the term also covers a person born in a regional processing country if a parent of that person was an unauthorised maritime arrival at the time of their birth, regardless of where that parent was at the time of birth. Unless the Minister exercises the power conferred by s 198AE to disapply s 198AD, s 198AD(2) requires that unauthorised maritime arrivals detained under s 189 of the Migration Act must be taken to a regional processing country. For this purpose, an officer of the Commonwealth is empowered by s 198AD(3) to place or restrain the unauthorised maritime arrival on a vehicle or vessel, to remove such a person from the place where he or she is detained or a vehicle or vessel, and to "use such force as is necessary and reasonable". 14 Section 198AHA of the Migration Act, which is in Subdiv B of Div 8 of Pt 2 of that statute, and is central to the Commonwealth parties' case, provides: 198AHA Power to take action etc. in relation to arrangement or regional processing functions of a country (1) This section applies if the Commonwealth enters into an arrangement with a person or body in relation to the regional processing functions of a country. (2) The Commonwealth may do all or any of the following: (a) take, or cause to be taken, any action in relation to the arrangement or the regional processing functions of the country; (b) make payments, or cause payments to be made, in relation to the arrangement or the regional processing functions of the country; (c) do anything else that is incidental or conducive to the taking of such action or the making of such payments. (3) To avoid doubt, subsection (2) is intended to ensure that the Commonwealth has capacity and authority to take action, without otherwise affecting the lawfulness of that action. (4) Nothing in this section limits the executive power of the Commonwealth. (5) In this section: action includes: (a) exercising restraint over the liberty of a person; and (b) action in a regional processing country or another country. arrangement includes an arrangement, agreement, understanding, promise or undertaking, whether or not it is legally binding. regional processing functions includes the implementation of any law or policy, or the taking of any action, by a country in connection with the role of the country as a regional processing country, whether the implementation or the taking of action occurs in that country or another country. 15 Notwithstanding that the focus of these provisions is the removal of unauthorised maritime arrivals to a regional processing country, there is provision in s 198B for a transitory person to be brought to Australia. Section 198B provides: (1) An officer may, for a temporary purpose, bring a transitory person to Australia from a country or place outside Australia. (2) The power under subsection (1) includes the power to do any of the following things within or outside Australia: (a) place the person on a vehicle or vessel; (b) restrain the person on a vehicle or vessel; (c) remove the person from a vehicle or vessel; (d) use such force as is necessary and reasonable. … 16 We also reproduce the terms of ss 198AD and 198AH, as follows: 198AD Taking unauthorised maritime arrivals to a regional processing country (1) Subject to sections 198AE, 198AF and 198AG, this section applies to an unauthorised maritime arrival who is detained under section 189. Note: For when this section applies to a transitory person, see section 198AH. (2) An officer must, as soon as reasonably practicable, take an unauthorised maritime arrival to whom this section applies from Australia to a regional processing country. (2A) However, subsection (2) does not apply in relation to a person who is an unauthorised maritime arrival only because of subsection 5AA(1A) or (1AA) if the person's parent mentioned in the relevant subsection entered Australia before 13 August 2012. Note 1: Under subsection 5AA(1A) or (1AA) a person born in Australia or in a regional processing country may be an unauthorised maritime arrival in some circumstances. Note 2: This section does not apply in relation to a person who entered Australia by sea before 13 August 2012: see the Migration Legislation Amendment (Regional Processing and Other Measures) Act 2012. Powers of an officer (3) For the purposes of subsection (2) and without limiting that subsection, an officer may do any or all of the following things within or outside Australia: (a) place the unauthorised maritime arrival on a vehicle or vessel; (b) restrain the unauthorised maritime arrival on a vehicle or vessel; (c) remove the unauthorised maritime arrival from: (i) the place at which the unauthorised maritime arrival is detained; or (ii) a vehicle or vessel; (d) use such force as is necessary and reasonable. (4) If, in the course of taking an unauthorised maritime arrival to a regional processing country, an officer considers that it is necessary to return the unauthorised maritime arrival to Australia: (a) subsection (3) applies until the unauthorised maritime arrival is returned to Australia; and (b) section 42 does not apply in relation to the unauthorised maritime arrival's return to Australia. Ministerial direction (5) If there are 2 or more regional processing countries, the Minister must, in writing, direct an officer to take an unauthorised maritime arrival, or a class of unauthorised maritime arrivals, under subsection (2) to the regional processing country specified by the Minister in the direction. (6) If the Minister gives an officer a direction under subsection (5), the officer must comply with the direction. (7) The duty under subsection (5) may only be performed by the Minister personally. (8) The only condition for the performance of the duty under subsection (5) is that the Minister thinks that it is in the public interest to direct the officer to take an unauthorised maritime arrival, or a class of unauthorised maritime arrivals, under subsection (2) to the regional processing country specified by the Minister in the direction. (9) The rules of natural justice do not apply to the performance of the duty under subsection (5). (10) A direction under subsection (5) is not a legislative instrument. Not in immigration detention (11) An unauthorised maritime arrival who is being dealt with under subsection (3) is taken not to be in immigration detention (as defined in subsection 5(1)). Meaning of officer (12) In this section, officer means an officer within the meaning of section 5, and includes a member of the Australian Defence Force. 198AH Application of section 198AD to certain transitory persons (1) Section 198AD applies, subject to sections 198AE, 198AF and 198AG, to a transitory person if, and only if, the person is covered by subsection (1A) or (1B). (1A) A transitory person is covered by this subsection if: (a) the person is an unauthorised maritime arrival who is brought to Australia from a regional processing country under section 198B for a temporary purpose; and (b) the person is detained under section 189; and (c) the person no longer needs to be in Australia for the temporary purpose (whether or not the purpose has been achieved). (1B) A transitory person (a transitory child) is covered by this subsection if: (a) a transitory person covered by subsection (1A) gives birth to the transitory child while in Australia; and (b) the transitory child is detained under section 189; and (c) the transitory child is a transitory person because of paragraph (e) of the definition of transitory person in subsection 5(1). (2) Subsection (1) of this section applies whether or not the transitory person has been assessed to be covered by the definition of refugee in Article 1A of the Refugees Convention as amended by the Refugees Protocol.

ARRANGEMENTS BETWEEN AUSTRALIA AND NAURU 17 The parties relied on a statement of agreed facts common to all of the proceedings. Broadly speaking, this statement outlined the arrangements between Australia and Nauru for the transfer of unauthorised maritime arrivals and for the provision of services to them. What follows is derived from the statement of agreed facts, including the accompanying documents. 18 Since 2013, the Australian Government policy has been that any person arriving in Australia by boat without a valid visa will not be permanently settled in Australia. 19 On 10 September 2012, the then Minister for Immigration and Citizenship designated Nauru as a "regional processing country" under s 198AB(1) of the Migration Act. On 3 August 2013, Australia and Nauru signed a document entitled "Memorandum of Understanding between the Republic of Nauru and the Commonwealth of Australia, relating to the Transfer to and Assessment of Persons in Nauru" (MOU). 20 The persons who were to be transferred to Nauru under the MOU were persons who: (a) have travelled irregularly by sea to Australia; or (b) have been intercepted at sea by Australian authorities or rescued in the course of trying to reach Australia by irregular means; and (c) are authorised by Australian law to be transferred to Nauru; and (d) have undergone short health, security and identity checks in Australia. 21 Under the MOU, Nauru agreed to "host" the Nauru Regional Processing Centres (RPCs). Nauru further agreed to enable the people it determined to be in need of international protection to settle in Nauru. Australia agreed to "bear all costs incurred under and incidental to this MOU as agreed". Clause 8 provided for the administrative measures to give effect to the MOU to be made at a later date. 22 On 11 April 2014, the Secretary of the Department of Immigration and Border Protection of the Commonwealth and the Minister for Justice of Nauru signed a document entitled "Administrative Arrangements for Regional Processing and Settlement Arrangements in Nauru" (Administrative Arrangements). 23 The Administrative Arrangements provided that "[c]onsistent with … the MOU … Australia will bear all costs incurred under and incidental to the MOU, including any reasonable costs associated with legal claims arising from activities under the MOU". The Administrative Arrangements included provisions for RPCs, allocating responsibilities regarding them between the two countries. It was provided that transferees were to be accommodated at a Regional Processing Centre (RPC) while their claims to be recognised as a refugee under Nauruan law were assessed. It was further provided that transferees determined to be in need of international protection were to be given "appropriate accommodation in Nauru until a durable solution is available". Clause 4.2.4 of the Administrative Arrangements provided that: The Governments of Australia and Nauru will, in exceptional circumstances, facilitate arrangements for the temporary return of [t]ransferees to Australia (for example, to enable a [t]ransferee to receive medical treatment). 24 The Commonwealth has entered into contracts for the provision of services on Nauru including: (a) contracts with Transfield Services (Australia) Pty Ltd (Transfield), which were in effect from 14 September 2012 to 31 October 2017; (b) a contract with International Health and Medical Services (IHMS) for the provision on Nauru of health services to persons transferred there by the Commonwealth parties and heads of agreement with IHMS for the provision of health services at a "Settlement Health Clinic" on Nauru; (c) a contract with Save the Children Australia (Save the Children); (d) a contract with Craddock Murray Neumann Lawyers Pty Ltd (Craddock Lawyers) in effect from 12 March 2013 to the present; (e) a contract with Adult Multicultural Education Services trading as AMES (AMES) in effect from 8 December 2014 to 7 December 2016; and (f) a contract with the Corporation of the Trustees of the Roman Catholic Archdiocese of Brisbane trading as Brisbane Catholic Education (Brisbane Catholic Education) in effect from 22 January 2016 to 21 January 2018. 25 In addition, the Commonwealth authorised the engagement by Transfield of Wilson Parking Australia 1992 Pty Ltd trading as Wilson Security (Wilson) pursuant to a contract between Transfield and Wilson for the provision by Wilson of services on Nauru. Transfield and Wilson subsequently entered into a subcontract relating to the provision of services on Nauru in 2013. The Commonwealth authorised a further subcontract between Transfield and Wilson Security Pty Ltd that was entered into in 2014. 26 The Commonwealth: (a) contracted for the construction and maintenance of, and funded, security infrastructure at the RPCs, including a perimeter fence; (b) funded, and continues to fund, all costs of the RPCs; (c) possessed and exercised rights under the contracts with Transfield; and (d) was able, while a person it had taken to Nauru was on Nauru, to request information regarding that person's health and welfare (among other matters) from the service providers it had entered into contracts with.

Facts not agreed 27 In a statement of facts not agreed, the Commonwealth parties alleged, and the Melbourne cohort did not agree, that the Commonwealth participated in their detention and the detention of their family members in so far as it did the things referred to in [26] above, and further that: (a) the Commonwealth had representatives on, and provided secretariat support to, governance bodies that advised and oversaw matters including the practical management of security services for the RPCs; (b) it undertook to provide security infrastructure at the RPCs, pursuant to the Transfield contract; and (c) it had step-in rights under the 2014 Transfield contract. 28 The Commonwealth parties alleged, and the Melbourne cohort did not agree, that the actions referred to in [27] above were authorised by s 198AHA(2) of the Migration Act. 29 In a separate statement of facts not agreed, the Commonwealth parties alleged and the Sydney cohort did not agree, in respect of the RPCs, that the Commonwealth, under s 198AHA(2) of the Migration Act had or did each of the things referred to in [27]. 30 Further, the Commonwealth parties alleged, and the applicants did not agree, that the Commonwealth's actions in making the Administrative Arrangements, entering into the contracts, funding the costs of the RPCs and doing any of the other things referred to in [22]-[26] above were authorised by s 198AHA(2) of the Migration Act. 31 The Commonwealth parties alleged, and the applicants did not agree, that: (a) the applicants and their family members were brought to Australia in exercise of the powers under s 198B of the Migration Act; and (b) the applicants and their families did not enter Australia as the holders of visas and have not been granted any visas since entering Australia. 32 Also in statements of facts not agreed, the Commonwealth parties said, and the applicants did not agree, that the applicants were found to be refugees by the Government of Nauru pursuant to Nauruan law. The Melbourne cohort said, and the Commonwealth parties did not agree, that it was irrelevant for the purposes of the Refugees Convention, to which Australia is a party, under which domestic law a person is determined to be a refugee. The Commonwealth parties said, and the Melbourne cohort did not agree, that in so far as the applicants and their family members were detained while on Nauru, they were detained by the Government of Nauru pursuant to Nauruan law.

OUTLINE OF EACH APPLICANT'S SITUATION 33 The circumstances concerning the individual applicants also bear on an understanding of the issues affecting the determination of the separate questions. The facts outlined below are derived from statements of agreed facts filed in each of the four proceedings. There were also separate statements of facts not agreed, one for each proceeding.

Applicant FRM17 34 FRM17 is represented by her mother, FRX17, in her capacity as FRM17's litigation representative. FRM17 is not yet a teenager. 35 FRM17 arrived on Christmas Island on 25 July 2013 with her mother, father and sister. Upon their arrival, officers of the Commonwealth (Commonwealth officers) took FRM17 and her family into immigration detention pursuant to s 189 of the Migration Act. About a month later, on or about 20 August 2013, Commonwealth officers took FRM17 and her family to Nauru. On or shortly before they arrived on Nauru, a Commonwealth officer made an application to the Secretary of the Department of Justice and Border Control of Nauru (relevant Nauruan authority) for RPC visas in respect of FRM17, her mother, father and sister. The Commonwealth parties alleged, and FRM17 did not agree, that the making of such applications was authorised by s 198AHA(2) of the Migration Act. 36 While on Nauru, the family's protection claims were considered and, as a result, on 22 September 2014, FRM17 and her family were determined by Nauru to be refugees. After they were found to be refugees, from on or about 20 October 2014 until about 20 December 2017, FRM17 and her family resided in the community on Nauru outside the RPCs. From 20 December 2017 to 24 December 2017, the family resided at the Restricted Accommodation Area (RAA) within the RPC. 37 Professional notes recorded that FRM17 reported that she attempted suicide on 9 December 2017 by taking an overdose of medication. At the time FRM17 was on Nauru, there were no tertiary level specialist child mental health facilities there. In a statement of facts not agreed, FRM17 alleged, and the Commonwealth parties did not agree, that professional notes recorded that FRM17 continued to express suicidal ideation after 9 December 2017 and that she was variously described in professional notes as being assessed at moderate risk of self-harm and having been diagnosed with adjustment disorder and anxious mood. 38 On 14 December 2017, an advocate for FRM17 separately emailed the Chief Medical Officer of the then Department of Immigration and Border Protection and IHMS. On 15 December 2017, FRM17's legal representatives emailed the Australian Government Solicitor (AGS). 39 On 20 December 2017, FRM17 commenced proceedings in this Court by filing an originating application, an application for urgent interlocutory relief and supporting affidavits. On 22 December 2017, a judge of the Court made orders, including that the Commonwealth parties place FRM17 in a specialist child mental health facility. The Commonwealth parties alleged, and FRM17 did not agree, that there were no tertiary level specialist child mental health facilities in Nauru or Papua New Guinea (PNG). 40 On 24 December 2017, FRM17 arrived in Australia with her mother and sister. They remain in Australia. 41 On 24 December 2018, the Commonwealth sought to file an interlocutory application seeking an order that FRM17's originating application be set aside on the basis that the Court lacked jurisdiction to entertain it. That application was accepted for filing by the Court on 24 January 2019. 42 On 11 January 2018, FRM17 filed a statement of claim (amended on 16 March 2018 and 6 March 2019) seeking damages and an injunction. 43 On 27 April 2018, the Commonwealth parties filed a defence (amended on 20 March 2019). In their amended defence the Commonwealth parties raised the question of s 494AB of the Migration Act as a bar to the proceeding being instituted or continued in this Court.

Applicant DLZ18 44 DLZ18 is represented by her father, DMA18, in his capacity as her litigation representative. DLZ18 is about the same age as FRM17. She was born in Iran. She and her family claim to be Kurds persecuted in Iran on account of their ethnicity. DLZ18's mother, FZR18, is the second applicant in this proceeding. 45 The involvement of the Commonwealth parties in the life of DLZ18 and her family began on 26 July 2013, when an Australian naval vessel intercepted the boat carrying DLZ18 (then quite a young child) and her parents. This naval vessel took DLZ18 and her family to Christmas Island, where Commonwealth officers detained her and her parents in immigration detention pursuant to s 189 of the Migration Act. Some six weeks later, on 4 September 2013, Commonwealth officers took DLZ18 and her family to Nauru. 46 On or shortly before their arrival on Nauru, a Commonwealth officer made an application to the relevant Nauruan authority for RPC visas in respect of DLZ18 and her parents. (The Commonwealth parties alleged, and DLZ18 did not agree, that the making of such applications was authorised by s 198AHA(2) of the Migration Act.) 47 They were each granted an RPC visa upon their arrival in Nauru and resided in the Nauru RPCs from 5 September 2013 until 21 January 2015. During this time, the family's protection claims were considered and, as a result, on 28 December 2014, DLZ18 and her family were determined by Nauru to be refugees. After this determination was made, DLZ18, her mother and father resided in the community of Nauru. 48 DLZ18 and her mother (FZR18) allege and the Commonwealth parties do not agree that, during her time on Nauru, DLZ18 was variously described in professional notes as having or being diagnosed with anorexia, a depressive disorder, and suicidal ideation. DLZ18 and her mother allege, and the Commonwealth parties do not agree, that in October 2018, DLZ18's father (DMA18) informed their solicitor that DLZ18 had self-harmed while alone in the hospital while her mother (FZR18) was hospitalised and he was detained in Villawood Immigration Detention Centre. 49 DLZ18 and FZR18 allege and the Commonwealth parties do not agree that during her time on Nauru, FZR18 was variously described in professional notes as having, or being diagnosed with, a depressive disorder with anxious features and being at moderate risk of self-harm or suicide. 50 Further, DLZ18 and her mother allege and the Commonwealth parties do not agree that in July 2018, DLZ18 was admitted to the Children's Hospital at Westmead with diagnoses of pervasive refusal syndrome, post-traumatic stress disorder, separation anxiety, malnutrition, vitamin D deficiency and profound deconditioning. DLZ18 and her mother allege and the Commonwealth parties do not agree that since her transfer to Australia, professional notes reflect that FZR18 was admitted to psychiatric facilities multiple times. 51 On 4 July 2018, DLZ18 commenced proceedings in this Court seeking damages and urgent interlocutory relief by way of an interlocutory application. An originating application (amended on 22 November 2018) and supporting affidavits were also filed at that time. The Commonwealth parties alleged, and DLZ18 and her mother did not agree, that Australia was the only place to which they could be brought having regard to the timeframes and nature and scope of the medical care sought in their interlocutory application. 52 On 6 July 2018, DLZ18 and her mother (FZR18) boarded a 6:30am flight from Nauru arriving in Brisbane around 9:00am Brisbane time. On that same day, at about 10:30am, a judge of the Court dismissed the interlocutory application filed two days before. 53 On 9 September 2018, DLZ18's father arrived in Australia. DLZ18, her mother and father remain in Australia. 54 On 22 and 28 November 2018, DLZ18 (joined by her mother as a second applicant) filed an originating application and a statement of claim respectively. 55 On 19 December 2018, the Commonwealth parties filed a defence to the statement of claim filed on 28 November 2018. In their defence the Commonwealth parties raised the question of s 494AB of the Migration Act as a bar to the proceeding being instituted or continued in this Court.

Applicant BXD18 56 BXD18 is a child. Marie Theresa Arthur is her litigation representative. Like DLZ18 and FRM17, BXD18 came by sea to Christmas Island with members of her family to seek asylum in Australia. On arriving on Christmas Island on 11 November 2013, BXD18, her father and brother were detained by Commonwealth officers in immigration detention pursuant to s 189 of the Migration Act. Commonwealth officers took BXD18, her father and brother to Nauru shortly afterwards. 57 On or shortly before their arrival on Nauru, a Commonwealth officer made an application to the relevant Nauruan authority for visas in respect of BXD18, her father and brother. (The Commonwealth parties alleged, and BXD18 did not agree, that the making of such applications was authorised by s 198AHA(2) of the Migration Act.) 58 On their arrival in Nauru, on or about 14 November 2013, BXD18, her father and brother were detained at a RPC. 59 While on Nauru, the family's protection claims were considered and, as a result, on 15 March 2015, BXD18, her father and brother were determined by Nauru to be refugees. They subsequently resided in the community of Nauru. 60 On 13 April 2018, BXD18 commenced proceedings in this Court seeking damages and an interlocutory injunction. An originating application, interlocutory application, statement of claim (amended on 27 August 2018) and supporting affidavits were filed at that time. The Commonwealth parties agreed to transfer BXD18 to Australia for medical treatment, accompanied by her father and brother. The Commonwealth parties did not raise the question of s 494AB of the Migration Act at that time. No orders for an interlocutory injunction were made. 61 On 15 April 2018, BXD18, her father and brother were brought to Australia. They remain in Australia. 62 On 19 November 2018, the Commonwealth parties filed their defence to BXD18's amended statement of claim, amongst other things raising the question of the bar in s 494AB of the Migration Act. 63 On 8 April 2019, BXD18 filed an amended reply to the Commonwealth parties' defence. On 9 April 2019, the Commonwealth parties filed a rejoinder to the amended reply.

Applicant DIZ18 64 DIZ18 is represented by her father, DJA18, in his capacity as her litigation representative. DIZ18 was born on Nauru and is now three years old. Her father and mother are Iranian nationals. 65 Before 13 September 2013, DIZ18's parents had been held in immigration detention in Australia. On or about that date, Commonwealth officers took them to Nauru. On or shortly before their arrival on Nauru, a Commonwealth officer made an application to the relevant Nauruan authority for visas in respect of DIZ18's parents. (The Commonwealth parties alleged, and DIZ18 did not agree, that the making of such applications was authorised by s 198AHA(2) of the Migration Act.) 66 When they arrived on Nauru, DIZ18's parents were detained at a RPC. 67 While DIZ18's parents were on Nauru, their protection claims were considered and, in consequence, on or before 15 July 2014, they were determined by Nauru to be refugees. Thereafter they resided in the community of Nauru. 68 On or before 22 November 2016, DIZ18 was recognised on Nauru as a refugee. 69 On 11 June 2018, DIZ18 was transferred to the health clinic, located in the Nauru RPC and run by IHMS, with a 6-day history of fevers that were not responding to treatment. (IHMS provides primary and mental health care services to people in immigration detention, including on Nauru, under a contract with the Commonwealth: see [24] above.) 70 By 12 June 2018, the medical advice to the Commonwealth parties was that DIZ18 needed to be evacuated from Nauru urgently and taken to a first world tertiary hospital and/or a centre with a specialist paediatric intensive care unit. 71 On 12 June 2018, DIZ18 was transferred to the Republic of Nauru Hospital, and then returned to the health clinic run by IHMS for further treatment. 72 On or around 14 June 2018, Commonwealth officers determined that DIZ18 and her mother (DJB18) should be transported to Port Moresby, PNG. The Commonwealth parties made arrangements and took all necessary actions to transfer them to the Pacific International Hospital (PIH) in Port Moresby, for DIZ18 to receive medical treatment. Her father (DJA18) remained on Nauru. The parties agreed that at all relevant times the PIH was not a first world tertiary hospital and that it did not have a specialist paediatric intensive care unit. 73 DIZ18 remained a patient at the PIH between 14 June 2018 and 4 July 2018. On or prior to 27 June 2018, the Commonwealth parties determined that DIZ18 and her mother (DJB18) would be taken back to Nauru from PNG. 74 On 29 June 2018, DIZ18 brought proceedings in this Court seeking an urgent interlocutory injunction. An originating application, interlocutory application, statement of claim (amended on 1 March 2019) and supporting affidavits were filed at that time. Orders were made on 3 July 2018 requiring that, as soon as reasonably practicable, DIZ18 and her mother (DJB18) be brought to Australia, and that her father (DJA18) be brought to Australia by 6 July 2018. The Commonwealth parties did not raise the question of s 494AB of the Migration Act at that time. 75 On 4 July 2018, the Commonwealth parties took DIZ18 and her mother (DJB18) from PNG to Australia. On the same day, the Commonwealth parties took her father (DJA18) from Nauru to Australia to be with DIZ18 and DJB18. They remain in Australia. 76 The Commonwealth parties filed their defence to the amended statement of claim on 19 March 2019. In their defence the Commonwealth parties raised the question of s 494AB of the Migration Act as a bar to the proceeding being instituted or continued in this Court. 77 DIZ18 filed her reply on 2 April 2019. The Commonwealth parties filed a rejoinder to the reply on 9 April 2019.

Applicants FRM17, DLZ18, BXD18 and DIZ18 78 As regards all applicants in the four proceedings, the parties further agreed on the following facts. 79 Both prior to the determination that they were refugees, and after that determination, the Commonwealth paid for: (a) all of the services provided to FRM17 and DLZ18 (and their respective family members) on Nauru by IHMS, Save the Children and AMES; (b) all of the services provided to BXD18 and DIZ18 (and their respective family members) on Nauru by IHMS, Save the Children, Craddock Lawyers and AMES; and (c) all visa fees payable to Nauru in respect of FRM17, DLZ18, BXD18 and DIZ18 (and their respective family members). 80 While the applicants and their family members were residing in the community on Nauru, the Commonwealth funded their financial income support payments and also met their accommodation and utility costs. 81 In respect of the matters set out at [79] and [80] above, however, the Commonwealth parties alleged, and the applicants did not agree, that the Commonwealth's actions were authorised by s 198AHA(2) of the Migration Act. 82 There were a number of other factual and associated matters in dispute between BXD18 and the Commonwealth parties, but it is unnecessary to set them out in detail here.

THE PARTIES' SUBMISSIONS 83 Before turning in more detail to the parties' respective pleadings, it may be useful to paint the broad parameters of the present dispute.

(a) The Commonwealth parties' submissions summarised 84 The Commonwealth parties submitted that the separate questions should be answered "yes" in all four proceedings. In brief, they submitted that this was because: (a) the proceedings concern actions taken by them (including the taking of the applicants to Nauru, the contracting of services provided to the applicants, and the bringing of the applicants to Australia) and, therefore, the proceedings "relate to" the exercise of statutory powers under the Migration Act which engage the bar in ss 494AB(1)(a), (ca) and (d) of the Migration Act; (b) Subdiv B of Div 8 of Pt 2 and s 198B of the Migration Act, which authorised actions of the Commonwealth in relation to regional processing, must be considered in determining the applicants' claims in negligence and, therefore, ss 494AB(1)(a) and (ca) apply; (c) properly construed, s 494AB is intended to capture "tort-based proceedings" concerning the exercise (or non-exercise) of regional processing powers; and (d) the pleadings and evidence in each case rely on or dispute actions taken (or not taken) under the regional processing provisions and/or s 198B, and seek relief preventing the removal of the applicants from Australia. Each case therefore raises factual issues and allegations about the statutory provisions that engage ss 494AB(1)(a), (ca) and (d). 85 Senior counsel for the Commonwealth parties explained at the hearing that the "narrowest" construction advanced by the Commonwealth parties is that, at the very least, the bar captures "proceedings which depend upon the statute", not in the sense that the statute is sued upon because of an allegation of breach of statutory duty, but in the sense that "the rights and liabilities asserted by a claimant depend upon the statute, their consistency with the statute". He reiterated, however, that the Commonwealth parties also advanced a broader construction, that it is sufficient for a proceeding to "relate to" the exercise of a statutory power if the duty or the breach of duty involves an analysis of the terms of the legislation. 86 Referring to O'Grady v Northern Queensland Co Ltd [1990] HCA 16; 169 CLR 356 at 367-368 (Dawson J), 372-374 (Toohey and Gaudron JJ), 377 (McHugh J), the Commonwealth parties submitted that under s 494AB(1) the question was "which Court has jurisdiction", there being no reason to read any component of s 494AB narrowly in order to safeguard access to the courts, because s 494AB only requires a party to go to a particular court, namely the High Court. The Commonwealth parties further submitted that the bar in s 494AB applied whenever the nexus between a proceeding and any topic in s 494AB is more than insubstantial or tenuous. They argued that this approach to the provision's construction best served its purpose, which was to limit litigation in the courts with respect to regional processing to the extent constitutionally permissible. The Commonwealth parties added that, in light of the clear purpose of limiting litigation, the presumption against ouster of jurisdiction (invoked by the applicants in support of a narrow construction of the provision) did not assist. They also submitted that a narrow construction of "proceedings relating to" was apt to produce uncertainty. Acknowledging that a proceeding may involve more than one matter, the Commonwealth parties submitted that s 494AB applied where any matter or issue in a proceeding involved a topic identified in s 494AB, including where that topic was identified in a defence. In this regard, the Commonwealth parties added that "[t]here is an obvious parallel with the principles concerning accrued jurisdiction, where it is well established that the whole proceeding will be in federal jurisdiction if any part of it is in federal jurisdiction". 87 At the hearing, senior counsel for the Commonwealth parties submitted that on its face, the bar applies "to all proceedings, and in all courts, whatsoever their origin or howsoever the proceedings arise. There is no a priori or ex facie exclusion of any kind with respect to particular classes of proceedings, suits, claims, demands or actions". The Commonwealth parties submitted that it would be wrong to construe s 494AB as applying only to judicial review proceedings, having regard to the statutory context, the language of s 494AB(3) (and the parallel provision, s 494AA(3)), and the definition of "Commonwealth" in s 494AB(4) (and s 494AA(4)). Further, there was, so the Commonwealth parties submitted, no basis for the proposition that proceedings in tort relating to the exercise of the powers in ss 198AD(3) and 198B(2) were intended to lie outside the bar in s 494AB (and the separate bar in s 494AA). The Commonwealth parties also submitted that, having regard to the legislative history of the relevant provisions, s 494AB(1)(ca) should be construed in a way that "cohere[s] with s 494AA(1)(e); and since tort claims do not lie outside s 494AA, there was no warrant for suggesting a different result in relation to s 494AB." Thus, the Commonwealth parties contended that the phrase "relating to" in s 494AB(1)(ca) should be construed to extend to actions in tort. 88 In reply, the Commonwealth parties submitted (citing Commissioner of Stamps (SA) v Telegraph Investment Co Pty Ltd [1995] HCA 44; 184 CLR 453 at 463 (Brennan CJ, Dawson and Toohey JJ); R v Seller [2013] NSWCCA 42; 273 FLR 155 at [100] (Bathurst CJ); and s 11B(1) of the Acts Interpretation Act 1901 (Cth)) that the Melbourne cohort's analysis of the legislative history was incorrect because it did not take into account that "the modern approach to the construction of an amended statute" was that "both the Act which is amended and the amending Act are to be read together as a combined statement of the will of the legislature", with the result that whatever the meaning of s 494AB before amendment(s) of it (and other provisions of the Act), "it must now be construed in the light of that amendment". They contended, in particular, that the retrospective operation of s 198AHA cannot be ignored or passed over as the Melbourne cohort seeks to do. 89 The Commonwealth parties argued that the separate questions should be answered by reference to the claims made by the parties, judged by reference to "the form and substance of the originating application, pleadings and interlocutory orders sought upon institution of the proceedings". In support of their contention that the bar applies in these four proceedings, the Commonwealth parties repeated their contention that the legislature intended that tort-based proceedings concerning the exercise (or non-exercise) of regional processing powers would come within s 494AB. They further submitted that, in any event, the resolution of the disputed factual and legal issues in the proceedings would require consideration of the application and effect of the regional processing provisions in relation to the applicants, each of whom is a transitory person. In particular, they argued that the proceedings "relate to" the exercise of powers under Subdiv B, engaging s 494AB(1)(ca), because: (a) The Melbourne cohort either deny or do not admit the Commonwealth parties' allegations that certain critical actions were authorised by s 198AHA. Whether these actions were so authorised is therefore an issue in each proceeding. In written submissions, the Commonwealth parties contended that the Sydney cohort had subsequently adopted the same position in written correspondence. At the hearing, Mr Watson SC stated that this was incorrect. Unlike the Melbourne cohort, the Sydney cohort did not file a reply in either proceeding, but the statement of facts not agreed for the Sydney cohort tends to confirm that they had adopted a similar position to the Melbourne cohort with respect to whether s 198AHA authorised certain conduct referred to in their pleadings (see statement of facts not agreed for the Sydney cohort, eg, at [1], [3] and see also the discussion of the parties' pleadings below). (b) Sections 198AD and 198AHA are central to the duties of care and breaches of duty alleged by the applicants. For example, the applicants plead their subjection to the regional processing regime (see s 198AD) as a material fact giving rise to the duties of care alleged by them. Further, the applicants plead other alleged acts and alleged omissions, relevant to both duty and breach, which the Commonwealth parties say were authorised by s 198AHA. The Commonwealth parties submitted that whether performance of the duty imposed by s 198AD can materially contribute or give rise to a duty of care is therefore a significant issue between the parties. They also contended that there is a further issue as to whether the exercise of regional processing functions, duties and powers is capable of, and did, attract a common law duty of care. 90 The Commonwealth parties submitted that the statutory framework within which public officials operate is relevant to all the elements of a cause of action in negligence. Citing Graham Barclay Oysters Pty Ltd v Ryan [2002] HCA 54; 211 CLR 540, Stuart v Kirkland-Veenstra [2009] HCA 15; 237 CLR 215 and Sullivan v Moody [2001] HCA 59; 207 CLR 562, the Commonwealth parties contended that an allegation that they failed to take certain actions only has significance if the Commonwealth parties had the power to take those actions; and since the primary source of power with respect to these actions is s 198AHA (in Subdiv B) the negligence claims necessarily "relate to" Subdiv B. Furthermore, the Commonwealth parties also relied on the proposition that, in determining the existence of any asserted duty of care, the Court would be required to consider "the consistency or otherwise of the asserted duty of care with the terms, scope and purpose of the relevant statute" and, in consequence, to consider how ss 198AD, 198AE and 198AHA should inform the factual and legal analysis of the issues in the proceedings. In this context, they relied on Crimmins v Stevedoring Industry Finance Committee [1999] HCA 59; 200 CLR 1 and Sutherland Shire Council v Heyman [1985] HCA 41; 157 CLR 424 at 459, 500, in addition to other cases. The Commonwealth parties argued that it was immaterial whether the applicants' actions were for negligence or for breach of statutory duty. The Commonwealth parties submitted, moreover, that the applicants misstated the effect of their own pleadings. 91 At the hearing, senior counsel for the Commonwealth parties helpfully explained their position in the following terms: [W]hat is absolutely clear on the authorities … is that in a context such as the present, no duty of care, as a matter of law, that is under the general law, can ever exist simply on the basis of knowledge, foreseeability and vulnerability. They are necessary, but not sufficient matters which may in a particular case feed into consideration of whether a duty of care is owed, but … if a proper consideration of the statute leads to the conclusion that a duty of care is not owed, then no amount of attention or focus upon knowledge, foreseeability and vulnerability can undo that outcome. 92 Furthermore, the Commonwealth parties submitted that s 494AB(1)(a) applies because the applicants allege that the Commonwealth parties ought to have brought them to Australia, which, so the Commonwealth parties say, would involve an exercise of the power in s 198B. The Commonwealth parties further submitted that in so far as applicants FRM17, BXD18 and DIZ18 seek to avoid removal from Australia, then s 494AB(1)(d) applies. 93 The Commonwealth parties also contended, in written submissions in reply, that the Melbourne cohort's passing suggestions in written submissions that the High Court lacks power to remit proceedings to which s 494AB apply to any other court should be rejected if they were truly pressed (which they ultimately were at the hearing), observing that, in Plaintiff S156/2013 v Minister for Immigration and Border Protection [2014] HCA 22; 254 CLR 28 at [20], the High Court had expressly approved the power to remit proceedings caught by s 494AA(1)(e) in answer to a formal question put to it, and there is no reason to read s 494AB any differently. The Commonwealth parties submitted that the High Court's power to remit "cures most, if not all, procedural issues that might be thought to arise".

(b) The applicants' submissions summarised 94 The applicants submitted that the separate questions should be answered "no". This is primarily because they contended that the claims are common law negligence claims, which they say is demonstrated by their pleadings. They contended that claims of this kind do not fall within any part of s 494AB of the Migration Act and the bar does not apply. In particular, in written submissions filed before the hearing, the Sydney cohort argued that: (a) regarding s 494AB(1)(a), there is no allegation of negligence in respect of the decision to bring, or manner of bringing, the applicants to Australia; (b) regarding s 494AB(1)(ca), there is no complaint regarding anything that occurred before the applicants arrived on Nauru; and (c) regarding s 494AB(1)(d), there is no complaint made by the applicants in respect of their removal from Australia. 95 Mr Horan QC, for the Melbourne cohort, submitted that, properly construed, ss 494AB(1)(a), (ca) and (d) are directed to proceedings challenging: (a) the exercise of (or failure to exercise) the power conferred by s 198B; (b) the performance of a function or duty or exercise of a power located in Subdiv B, which has been, or is threatened to be, exercised in relation to a transitory person; and (c) the removal of a transitory person from Australia under the Migration Act. Mr Horan QC submitted that the context and purpose of s 494AB, the presumption against ouster of jurisdiction, and the inconvenience of the Commonwealth parties' approach indicated that the Commonwealth parties' overly-broad construction of s 494AB was in error. Mr Horan QC argued that, on the Commonwealth parties' construction, s 494AB would extend to all civil claims, such as a proceeding involving an action for damages for breach of contract by a supplier of goods or services to the Commonwealth on Nauru where such goods or services are used in relation to a transitory person. He posited practical and other difficulties arising from the Commonwealth parties' construction, arguing that the Commonwealth parties' approach "requires the parties and the courts to continually scrutinise the shifting sands of the proceedings progress, including any amendments to pleadings of defences, counterclaims, etc." Mr Horan QC submitted that the character of a proceeding "can be identified from the claims that are made and the relief sought", and that character does not change, so as to bring into effect the bar, depending on the course of pleadings, evidence or submissions. Amongst other things, considerations such as these led the Melbourne cohort to submit that "the 'mischief' is commencement of a proceeding; s 494AB(1) also addresses continuation, in order to deal with cases where the effect of the statutory bar might not have been appreciated at that time". The applicants contended that the federal jurisdiction analogy relied on by the Commonwealth parties is inapt and should be rejected. 96 The applicants also submitted that the purposes of s 494AB(1) advanced by the Commonwealth parties should not be accepted. They argued that if, as the Commonwealth parties said, by virtue of s 494AB(1), all litigation with respect to regional processing must be commenced in the High Court, with a view to being remitted to this or another court, then the provision did not "limit" anything; and that this was an untenable construction. Mr Horan QC argued that there is limited, if any, support in the statutory text, legislative history or extrinsic materials for that construction. 97 Mr Horan QC submitted that the purpose of s 494AB was to limit only "certain legal proceedings" with the object of "stop[ping] legal proceedings being taken in relation to the transitory person's presence in Australia". He argued that the mischief to which ss 494AB(1)(a), (ca) and (d) is directed is "a form of scrutiny of proceedings when review is sought of the exercise of powers and functions or the performance of duties under the Act". It was said that the legislative history of s 494AB confirmed that only a narrow category of proceedings was to be affected by the bar (including because s 494AB(1)(ca) was part of the Migration Act before s 198AHA was introduced). 98 In response to the Commonwealth parties' submission that the applicants had wrongly sought to construe s 494AB as applying only to judicial review proceedings, Mr Watson SC emphasised in oral submissions that "at no time before or now has the Sydney cohort maintained that section 494AB is somehow limited only to circumstances of judicial review. We never said that; we never intended to say that". Mr Horan QC similarly rejected the Commonwealth parties' characterisation of their argument. 99 The applicants submitted that in determining whether the bar applies to these proceedings the Court must look at the substance of what has been pleaded. The applicants submitted that the proceedings did not fall within the bar simply because the interaction between the applicants and the Commonwealth parties occurred in the context of the Migration Act. It would be different, so they argued, if their claims were based on a breach of a statutory duty but that is not the basis of their case against the Commonwealth parties. Rather, the basis of the applicants' claims was, in the words of the Sydney cohort, that "the [Commonwealth parties] had placed themselves in a position where it was unavoidable that the applicants would rely on them"; and that, when the Commonwealth parties knew that the applicants were suffering psychological problems, they took inadequate steps to address them. In this regard, the Sydney cohort relied on Heyman at 461 (Mason J), 479 (Brennan J), Birch v Central West County District Council [1969] HCA 67; 119 CLR 652 at 658-659 (Barwick CJ) and Howard v Jarvis [1958] HCA 19; 98 CLR 177 at 183 (Dixon CJ, Fullagar and Taylor JJ). The Sydney cohort argued that the relationships between each of the applicants and the Commonwealth parties are similar to other relationships that are known to give rise to a duty of care, such as guardian/ward, gaoler/prisoner and teacher/pupil. The applicants argued that each of their claims is based upon the relationship between each applicant and the Commonwealth parties and that, although that relationship may have commenced in circumstances where a statutory power was exercised, this does not mean that the proceedings relate to that fact. At the hearing, Mr Watson SC contended that, properly understood, references in the pleadings to the Migration Act and the exercise of powers with respect to the regional processing regime merely operate at the level of "background" to the common law negligence claim pleaded in each case. 100 The Melbourne cohort added that "[t]he complete cause of action is pleaded without reference to a function, duty or power under the [Migration] Act". They submitted that "[t]here is no challenge (whether direct or collateral), to the validity of any actual or threatened exercise of (or failure to exercise) any function, duty, or power"; and that the relief sought was not directed to any power under the Migration Act. Further, so Mr Horan QC said, "[i]n characterising the proceeding, it is not even necessarily relevant whether or not the Respondents acted with lawful authority". Finally, Mr Horan QC argued that, "for all practical purposes", the "instituted" issue was moot (see s 494AB(1)). It was submitted, in this regard, that the Commonwealth parties were inviting this Court to conduct an ex post facto mini-trial of what the duty judge might have found at the interlocutory hearing on the basis of evidence that was not led. 101 The Sydney cohort added that, even if there was an issue about the existence of a duty, that issue would be resolved in favour of the applicants, and without any need to refer to the Migration Act. This was said to be because, having regard to the facts alleged in the applicants' pleadings, the applicants would satisfy the "salient features" test described in Caltex Refineries (Qld) Pty Ltd v Stavar [2009] NSWCA 258; 75 NSWLR 649 at [102]-[107] (Allsop P). 102 Further, the applicants argued that the Commonwealth parties' reliance on the line of cases including Graham Barclay Oysters, Stuart and Sullivan v Moody was misplaced. Mr Horan QC submitted that those cases simply support the proposition that "statute is relevant", and even important, "in informing a common law action in negligence", which the applicants do not deny; but "it remains a common law action". 103 Finally, it should also be noted that at the hearing Ms De Ferrari SC submitted on behalf of the Melbourne cohort that, as a matter of statutory construction, the High Court has no power to remit matters commenced in the High Court by reason of the bar in s 494AB(1). She submitted that there is no authority of any court (including Plaintiff S156) that goes against that proposition.

THE PARTIES' APPLICATIONS AND PLEADED CASES 104 The outcome of the separate questions depends on the resolution of some difficult issues of statutory construction and the proper characterisation of the four proceedings commenced and maintained in this Court by each of applicants FRM17, DLZ18, BXD18 and DIZ18, through their respective legal representatives. As the above overview of the parties' submissions indicates, this characterisation mostly depends on each party's pleaded case. What follows is an examination of the parties' pleadings, which is done in some detail because of the test case nature of these four proceedings.

Applicant FRM17 105 Proceedings were begun for applicant FRM17 by an originating application seeking an interim injunction restraining the Commonwealth parties from: (a) detaining FRM17 (and her mother and sister) on Nauru or at any other offshore regional processing centre not within Australia; and (b) not permitting FRM17 to travel to another country for the purpose of obtaining urgent psychiatric medical attention. As the originating application and the subsequent history of the proceeding make clear, FRM17 was, in substance, seeking appropriate medical treatment that she alleged could not be provided on Nauru or at another RPC, notwithstanding the terms of paragraph (a) of the interim injunction and [6] of the originating application might appear to indicate a wider focus. 106 The originating application included two claims for relief in [6] and [7] as follows: [6] Unless otherwise agreed in writing between [FRM17] and the Respondents, upon the Respondents discharging their duty to exercise reasonable care to obtain for [FRM17] urgent psychiatric care that is clinically recommended where that care is not provided to [FRM17] in Nauru or in any other off-shore environment and where the care is consistent with the expert psychiatric medical reports of Professor Louise Newman dated 19 December 2017 and Dr. Nick Martin dated 19 December 2017. [7] Unless otherwise agreed in writing between the legal representative of [FRM17] and the Respondent, the Respondent shall provide on an ongoing basis the psychiatric and medical care to [FRM17] as shall be clinically recommended by treating child psychiatrists or suitably qualified medical practitioners who are providing ongoing care to [FRM17]. The meaning of [6] is far from clear, but it does not appear to be a claim for injunctive relief. It may be that [7] is a claim for mandatory injunctive relief, but it does not relate to any of the provisions in Subdiv B. A separate interlocutory application filed at the same time sought FRM17's transfer to a location "where [FRM17] can receive the Specified Treatment".

Further amended statement of claim 107 FRM17's further amended statement of claim (FRM17's FASC) commenced in the conventional way with a description of the parties, including some of the matters that are now included in the separate statement of agreed facts pertaining to her and in the statement of agreed facts common to all the proceedings. By FRM17's FASC, through her litigation representative, she claimed damages and an injunction to require the Commonwealth parties' procurement of appropriate specialist child psychiatric health treatment in conditions where FRM17's social, educational, recreational and domicile needs are met. 108 It was pleaded (at [18]) that the Commonwealth owed FRM17 a duty to take reasonable care to avoid foreseeable harm to her to: (a) take reasonable care to ensure that her detention did not cause injury, or exacerbate existing injury; (b) provide reasonable health care in the event she suffered an injury and to prevent injuries; and (c) to exercise due care and skill in providing such care. 109 The facts from which the duty of care was said to arise included that: (a) FRM17 was detained on Nauru at a detention facility and other detention environments by the Commonwealth parties from about 21 August 2013 until her removal to Australia on 24 December 2017 (see FRM17's FASC at [3(c)]); (b) the Commonwealth has continued to take actions most of which are set out in [24]-[26] above and assumed responsibilities in relation to her under ss 198AHA(2)(a) and (c) of the Migration Act (see FRM17's FASC at [9(h)], [14]); (c) the Commonwealth, in exercise of its powers under s 198AHA of the Migration Act and/or s 61 of the Constitution, directed Nauruan officers such that while Nauruan management and control of the detention facility and other detention environments in which FRM17 lived was theoretically within the delegated authority of Nauruan officers, in practice and effect from 21 August 2013 until 24 December 2017 the Commonwealth maintained practical de facto financial and physical control over: (i) the day to day operation of the detention facility and the other detention environments in respect of FRM17 and her family; (ii) the placement of FRM17 and her family on Nauru as a place of detention; (iii) the placement and location of FRM17 in detention within the detention facility and the detention environments on Nauru (including Iijuw refugee camp); and (iv) restrictions on the movement of FRM17 within the detention facility. See FRM17's FASC at [15]; (d) the Commonwealth, in exercise of its powers under s 198AHA of the Migration Act and/or s 61 of the Constitution: (i) made arrangements for the care and welfare of FRM17 much of which is set out in [24]-[26] above pending her claim for refugee status pursuant to the MOU and Administrative Arrangements; (ii) provided food and water, shelter and accommodation, medical treatment and health care and physical security for FRM17 pursuant to the MOU and Administrative Arrangements; (iii) paid and provided for all aspects of her detention, care and maintenance for the duration of the time on Nauru pursuant to the MOU and Administrative Arrangements, including her visa in Nauru, her accommodation, all other fees payable in respect of her residence, and her education; (iv) was able to remove FRM17 on and off Nauru; (v) provided FRM17 with access to medical treatment and health care at no cost made through arrangements to pay IHMS to provide a Settlement Health Clinic within the detention facility; (vi) provided for the detention and services to FRM17's family; and (vii) has continued to assume responsibility for FRM17 in paying for her maintenance and health care since her arrival in Nauru pending her settlement. See FRM17's FASC at [16]; see also at [14]; and (e) at all material times while FRM17 was in detention on Nauru, the conditions to which she was subject were under the control of the Commonwealth and/or the Minister for Home Affairs, together with their servants and agents, including: (i) Transfield, which, by reason of the Transfield contracts, controlled who was able to visit, telephone or otherwise contact FRM17; and (ii) IHMS, which by reason of the Heads of Agreement, controlled who was able to provide medical care to FRM17. See FRM17's FASC at [17D]. 110 FRM17's FASC further pleaded the existence of a duty of care (at [22A]) (apparently said to arise from what FRM17 alleged the Commonwealth parties knew, or ought reasonably have known (at [22])) to take reasonable steps to ensure that FRM17 was provided with: (a) shelter and accommodation that was reasonably adapted to the tropical conditions of Nauru; (b) medical care and health services that were appropriate for a young child in the conditions as they existed at Christmas Island and on Nauru for both her mental and physical health; (c) access to reasonable amenities, opportunities for education, and recreational facilities; (d) reasonable protection from exposure to adult's self-harming or threatening to self-harm, and physical violence; and (e) reasonable protection from exposure to intimidation, discrimination, ostracization, bullying and/or other anti-social behaviours from other persons. A breach of this duty was pleaded at [23] of FRM17's FASC. 111 In FRM17's FASC (at [24]; particulars omitted) it was pleaded that: [FRM17] has been suffering from psychiatric and psychological injuries while on Nauru where her symptoms have included her being angry, violent, withdrawn, depressed and sad and where she experienced voices and had suicidal thoughts which she acted upon. 112 It was further pleaded (at [25]; particulars omitted) that FRM17: (a) has been harmed by the actions and failures of the Commonwealth parties since her detention in Australia in 2013; (b) has developed a psychiatric illness on Nauru which illness has not been appropriately diagnosed or treated; and (c) was harmed by the continued effective detention within the community on Nauru since February 2015. 113 FRM17's FASC alleged a further duty of care (at [31]) owed to FRM17, which was to: (d) develop a protocol for conducting a specialised developmentally-appropriate pre-RPC transfer mental health assessment for high risk children, including FRM17 on Christmas Island; (e) detain FRM17 in an environment that did not cause her to develop a psychiatric injury; (f) audit FRM17 to ensure that she was not suffering from any psychiatric or psychological conditions; (g) place FRM17 in a specialist child mental health facility with a comprehensive tertiary level child psychiatric assessment; (h) provide FRM17 with access to experienced child and adolescent mental health professional staff with a background in psychiatric nursing or psychology and experience in child mental illness; (i) procure a comprehensive psychiatric assessment of FRM17; (j) ensure such an assessment was conducted by a qualified specialist in child psychiatry; (k) ensure such treatment was procured in an inpatient child mental health facility; and (l) implement an effective safety plan including treatment and monitoring of FRM17. 114 Further pleaded facts from which this duty was said to arise included that: (a) the Commonwealth had made an agreement with Nauru that: (i) service providers would ensure that persons (including FRM17) maintain access to health services to the best available standard to a standard consistent with health care available to the Australian community; (ii) the Commonwealth will, in exceptional circumstances, facilitate arrangements for the temporary return of persons (including FRM17) to Australia to enable such persons to receive medical treatment; and (iii) special arrangements will be developed and agreed to for vulnerable cases, including unaccompanied minors. See FRM17's FASC at [26]; and (b) the Commonwealth in the exercise of powers under s 198AHA of the Migration Act and/or s 61 of the Constitution: (i) assumed responsibility for, and control over, FRM17 for the purpose of arranging to have her placed in a RAA in the detention facility to treat her illness; (ii) otherwise assumed responsibility and control of FRM17 in respect of her mental illness; (iii) paid for all costs incidental to FRM17's care and maintenance on Nauru; (iv) assumed effective control and responsibility over FRM17's mental health, wellbeing and safety; (v) is aware that FRM17 is entirely reliant on the Commonwealth to procure her adequate mental health treatment; (vi) decided that FRM17 could be adequately treated for her depression and persistent suicidality on Nauru and placed her within a RAA within the detention facility on Nauru for treatment; and (vii) is responsible for creating the detention facility environment on Nauru, and transferring FRM17 to Nauru, the environment of which is harmful to her. See FRM17's FASC at [27]. 115 There were further allegations in FRM17's FASC about the Commonwealth parties' knowledge (at [29]-[30]); and pleadings as to breach of duty (at [32]). There were extensive particulars given for these alleged breaches. There were also pleadings as to FRM17's vulnerability (at [33]), and pleadings about resultant injury (at [28] and [35]). The prayers for relief included damages and a permanent injunction which would have the effect of obliging the Commonwealth parties, within five days of the making of the order, to cease to fail to discharge their duty of care to procure specialist child psychiatric health treatment for FRM17.

Amended defence 116 Generally speaking, the Commonwealth parties' amended defence did not take issue with the description of the parties as pleaded in FRM17's FASC, although the Commonwealth parties' pleaded position was that, if FRM17 was detained while residing in the detention facility on Nauru, her detention was by the Nauruan Government under Nauruan law. The Commonwealth parties further pleaded that on the grant of a temporary settlement visa by the Nauruan Government, FRM17 was no longer subject to movement restrictions and was able to settle in the community on Nauru (see at [2(m)], [3(c)(vi)]). 117 The Commonwealth parties admitted (at [18]) that the Commonwealth owed FRM17 a duty of care to ensure that reasonable care was taken of her while she was detained on Christmas Island (prior to her transfer to Nauru), but otherwise denied any duty of care was owed by the Commonwealth parties to her when she was on Nauru. At [14] of their amended defence, the Commonwealth parties did not dispute some of their actions as set out at [22]-[26] above. 118 The Commonwealth parties admitted (at [16]): (a) entry into the MOU and the making of the Administrative Arrangements; (b) that the Commonwealth paid for all aspects of FRM17's accommodation, care and maintenance when she was housed in the detention facility; (c) that the Commonwealth contracted with, and paid for, IHMS to provide a Settlement Health Clinic within the detention facility and that FRM17 was able to access medical and health care at the clinic from IHMS at no cost to her; and (d) that the Commonwealth has power under s 198B of the Migration Act to bring a transitory person from Nauru to Australia for temporary purposes, although removal from Nauru was subject to the agreement of the Nauruan Government. 119 The Commonwealth parties denied the other alleged facts and matters on which FRM17 relied for a duty of care to avoid foreseeable harm to her on Nauru. The Commonwealth parties further pleaded (at [15]) that the day to day operation of the detention facility and the placement of FRM17 were matters for the Nauruan Government; and that Commonwealth officers assisted Nauruan officers in the management of the detention facility and refugee camp pursuant to intergovernmental agreements and s 198AHA of the Migration Act. 120 The Commonwealth parties denied (at [22A]) that they owed a duty of care of the kind pleaded at [22A] of FRM17's FASC: see [110] above. As to the pleading at [24] of FRM17's FASC (see [111] above), the Commonwealth parties pleaded: In relation to paragraph 24, the respondents; a. admit that [FRM17] had appointments with various medical professionals from time to time at which complaints were made as recorded in those professional's notes; and b. otherwise do not admit the allegation in paragraph 24. The Commonwealth parties denied the allegations in [25] of FRM17's FASC (see [112] above), and affirmed that FRM17 was brought to Australia pursuant to s 198B of the Migration Act on 24 December 2017. 121 The Commonwealth parties denied the existence of the duty of care pleaded in FRM17's FASC at [31] (see [113] above). As seen above, however, the Commonwealth parties admitted some of the facts and matters on which this alleged duty was apparently said to depend, including that the Commonwealth had entered into the Administrative Arrangements and a contract with IHMS to provide health services. The Commonwealth parties also admitted (at [26]) the allegation that, under an agreement with Nauru, the Commonwealth would, in exceptional circumstances, facilitate arrangements for the temporary return of persons to Australia for medical treatment and make special arrangements for vulnerable cases. In conformity with other parts of their pleading, the Commonwealth parties also admitted (at [27]) that the Commonwealth paid for accommodation and health care; and affirmed that they "reasonably believed that [FRM17] was receiving and could receive appropriate care on Nauru based on medical advice from IHMS". 122 The Commonwealth parties denied the further allegations made about their knowledge at [29]-[30] of FRM17's FASC and her pleadings (at [32]) as to breach of duty. They did not admit, or denied, the pleadings as to her vulnerability at [33], save to admit that FRM17 was a child, and they denied the resulting injury to FRM17 alleged in [28] and [35] of FRM17's FASC (see [115] above). 123 Lastly, the Commonwealth parties further pleaded: [38] In answer to the whole of the further amended statement of claim, the respondents say that the allegations made by the applicant concerning her transfer to and period in Nauru impermissibly invites the Court to apply the standard of negligence to decisions of high-level government policy, which involve or are dictated by economic, social and political factors, including the [Commonwealth's] relationship with foreign governments, and in respect of which the Court should not impose a duty of care. [39] In further answer to the whole of the amended statement of claim, the respondents say that [FRM17's] transfer to Nauru was lawful and pursuant to s 198AD of the [Migration] Act and that the imposition of a duty of care in relation to her lawful transfer to and period in Nauru would be incompatible with: a. the statutory duty contained in s 198AD(2) of the [Migration] Act; and b. the purpose of subdivision B of Division 8 of Part 2 of the [Migration] Act. 124 Under the heading "Jurisdiction", the Commonwealth parties alleged that ss 494AB(1)(a), (ca) and (d) of the Migration Act applied to bar the proceeding because, among other things ss 198B, 198AD and 198AHA were engaged (see at [40]-[48]).

Applicant DLZ18 125 As already indicated, the proceedings in this Court for DLZ18 were commenced by the filing of an originating application on 4 July 2018, together with an interlocutory application and supporting affidavits. An amended originating application was filed on 22 November 2018 and a statement of claim, on 28 November 2018. The Commonwealth parties filed their defence on 19 December 2018. 126 At the hearing, Mr Watson SC agreed with Mr Howe QC that none of the differences between the pleadings in each case in the Sydney cohort was material to the answers to the separate questions. Perusal of the pleadings in the cases of DLZ18 and FRM17 confirms that they substantially resemble one another. In these circumstances, it is unnecessary to consider the pleadings in DLZ18's case in detail. We would, however, make the following general observations. 127 The statement of claim filed on behalf of DLZ18 and her mother FZR18 set out their pleadings under a number of specific headings. Included under the heading "Factual Matters" were the following allegations: [37] During the period of detention of the Applicant Family on Nauru, the applicants were required to live in conditions which were inappropriate for the development, welfare and education of the applicants, in particular [DLZ18], and the class of persons of which they were members (the Conditions on Nauru). [38] The Conditions on Nauru exposed the applicants to a risk of harm, including psychological harm. [39] From approximately late September 2013 - ie when the Applicant Family was transferred from Christmas Island to Nauru - the respondents were aware that the detention of the applicants, and the class of persons of which they were a member, on Nauru exposed them to a risk of harm including psychological harm. There were detailed particulars given for [37] and [39]. 128 There were detailed allegations (at [40]-[44]) in the statement of claim concerning DLZ18's mental and physical deterioration and allegations (at [45]-[54]) concerning the Commonwealth parties' knowledge and failure to take appropriate action in relation to DLZ18, and in relation to DLZ18's subsequent admission to hospital in Australia. There were equivalent allegations (at [66]-[71]) concerning FZR18's psychological health and the Commonwealth parties' knowledge. 129 Under the heading "Duty of Care", it was alleged: [72] At all material times, the respondents owed a common law duty of care, the content of which changed over time. [73] From 26 July 2013 the respondents owed the applicant a duty to ensure that reasonable care was taken of the applicants whilst they were detained under s 189 of the [Migration] Act on Christmas Island. [74] From approximately late September 2013 - ie when the applicants were transferred from Christmas Island to Nauru - the respondents owed the applicants a duty to take reasonable care: 74.1 To protect the applicants from unreasonable risks of harm, including psychological and physical harm, following their removal from Christmas Island and their relocation to Nauru; 74.2 To monitor the condition of the applicants to ascertain whether the Conditions on Nauru were having a deleterious effect upon the applicants; 74.3 To take measures, including the provision of appropriate medical treatment, in the event the applicant manifested adverse effects. 130 There followed allegations as to the Commonwealth parties' state of knowledge concerning DLZ18 and FZR18's deteriorating health (at [75]-[78]), an allegation of breach of duty (at [79]), and allegations of psychological injuries suffered by each of DLZ18 and FZR18 (at [80]-[81]). At [82], it was alleged that: The breach by the respondents of the duty of care owed to the applicants: 82.1 Caused the applicants to suffer the Psychological Injury; or 82.2 Alternatively, worsened or aggravated the applicants' Psychological Injuries. By way of relief, damages were sought. 131 The Commonwealth parties' defence did not materially differ from their defence in FRM17's case. In particular, the Commonwealth parties' answers to [37] of the statement of claim filed for DLZ18 and her mother (see [127] above) included a denial and an assertion that: [W]hile the Applicant Family were residing in the RPC, the day-to-day operation of the RPC, the placement and location of the members of the Applicant Family were matters for the Government of Nauru to be determined pursuant to the laws of Nauru[.] 132 A significant number of the critical allegations in [38]-[54] and [66]-[78] of the statement of claim filed for DLZ18 and her mother were denied or not admitted, including the existence of a common law duty of care owed by the Commonwealth to DLZ18 whilst she was on Nauru (at [74]). In answer to [74], the Commonwealth parties included an allegation that "the actions which the alleged duty of care required the Commonwealth parties to undertake would have required the Commonwealth to exercise powers under s 198AHA and/or an officer to exercise power under s 198B". A similar allegation is made elsewhere in the Commonwealth parties' defence, including at [75.3], [76.3], [77.3] and [78.3]. At [78B], the Commonwealth parties further alleged: In further answer to paragraphs 74, 75, 76, and 77, the second respondent denies the existence of the alleged duty or duties of care because: 78B.1 they are incompatible with the control which the Government of Nauru exercised or could exercise over the applicants while in its territory; 78B.2 they are inconsistent with the scheme of the [Migration] Act, and in particular Subdivision B of Division 8 of Part 2 of the [Migration] Act and the assistance which the Commonwealth can render under those provisions in relation to an arrangement or regional processing functions of a country. 133 The Commonwealth parties did not admit or denied the allegations of injury and causation in [80]-[82] of the statement of claim. 134 At [84], the Commonwealth parties made claims about the law applicable to alleged acts or omissions of the Commonwealth parties during the period the applicants were detained in Nauru and Christmas Island; and also made the same allegations that appear in their defence to FRM17's FASC at [38]-[39] (see [123] above). At [85]-[89], the Commonwealth parties set out their claims about the Court's lack of jurisdiction by reason of the bar in ss 494AB(1)(a) and (ca) of the Migration Act. (We note that the reference in the defence to s 494AB(1)(b) is a clear typographical error.)

Applicant BXD18 135 The case of BXD18 was part of the Melbourne cohort. This proceeding was begun when an originating application was filed (seeking injunctive and declaratory relief and damages) along with a statement of claim and an interlocutory application seeking, amongst other things, an order that the first respondent "immediately transfer" BXD18, together with her father and brother, to a location where BXD18 could receive an immediate psychiatric assessment and treatment in an inpatient child mental health facility (among other things). An amended statement of claim was filed on 27 August 2018. The Commonwealth parties filed their defence on 19 November 2018. 136 At the hearing, Mr Horan QC and Mr Watson SC agreed that, for the purposes of answering the separate questions, there was no material difference in the pleadings between the Melbourne cohort and the Sydney cohort. Mr Howe QC observed that the Commonwealth parties accepted that there was no material difference so far as the pleadings were concerned between the applicants within the Melbourne cohort. Mr Horan QC did not disagree with this proposition. 137 As will become apparent, however, we consider that there are some relevant differences which do affect the outcome. 138 At [13] of the amended statement of claim in BXD18's case, it is alleged that the Commonwealth parties owed BXD18: a. a duty of care to take reasonable care to prevent her from suffering psychiatric injury and from suffering physical, emotional and/or child abuse; b. a duty to ensure that the service providers exercised reasonable care to prevent her from suffering psychiatric injury and from suffering physical, emotional and/or child abuse … . 139 The facts and matters relied on to give rise to this duty are set out at [4]-[12] of BXD18's amended statement of claim and included: (a) the designation of Nauru as a "regional processing country" under s 198AB(1) of the Migration Act (at [4]); (b) the Commonwealth's entry into the MOU and the Administrative Arrangements with Nauru (at [5]-[6]); (c) the circumstances in which BXD18 and her family members came to Australia, their detention on Christmas Island, their detention and residence on Nauru, as well as other of the Commonwealth parties' actions and their assumption of responsibilities in relation to her (at [7]); (d) facts and matters of the kind set out above at [24]-[26] and 109-(d) (at [9]-[10]); (e) assumed responsibility for BXD18's and her family members' health and welfare (at [9]); (f) the Commonwealth parties' knowledge about the risk of physical, emotional and child abuse on Nauru, and psychiatric injury (at [11]); and (g) BXD18's dependence on the Commonwealth parties, directly or through their service providers, for the provision of medical treatment, psychological and psychiatric treatment, welfare services, support services and educational services (at [12]). 140 There was a pleading at [14] concerning the standard of care applicable in the circumstances, which, in summary, was a set of statements about the steps that the Commonwealth parties should have taken to avoid their alleged breach of duty, including removing BXD18 from Nauru (at 14). At [16]-[18], it was alleged that: [16] At all relevant times the Respondents knew or alternatively ought to have known that a failure to act with reasonable care … would place [BXD18] at risk of: a. suffering physical, emotional and/or child abuse; b. suffering psychiatric injury. [17] In the premises, it was reasonably foreseeable that: a. not removing [BXD18] from Nauru; b. alternatively, continuing to keep [BXD18] and her family on Nauru, particularly after they were found to be refugees, while there existed non-negligible risks of physical, emotional and child abuse and of psychiatric injury, would lead to [BXD18] suffering physical, emotional and/or child abuse and/or suffering psychiatric injury. [18] In the premises: a. the Minister breached his duty of care to [BXD18]; b. the Commonwealth breached its duty of care to [BXD18]. 141 There were further allegations as to breach of duty by the Commonwealth parties' service providers and therefore by them (at [20]-[21]). It was further alleged (at [22]) that BXD18 had suffered injury, loss and damage as a result of: a. the Respondents' failure to remove [BXD18] from Nauru; b. alternatively, the Respondents' decision to continue to keep [BXD18] and each member of her family on Nauru, including by failing to resettle [BXD18] and each member of her family after each was found to be a refugee, with knowledge (actual, or which they ought to have had) that she would be at risk of physical, emotional and child abuse, and at risk of psychiatric injury; c. additionally and/or alternatively, the Respondents' failure to ensure that the service providers exercised reasonable care in relation to [BXD18]. Causational issues and loss and damage was further addressed at [23]-[26] of BXD18's amended statement of claim. 142 The claimed relief included damages and an injunction requiring the Commonwealth parties to resettle BXD18 and her family; alternatively, an injunction requiring the Commonwealth parties not to take steps to remove BXD18 and her family to any "regional processing country" where she would be at risk of the same damage she allegedly suffered in Nauru; alternatively, an injunction requiring the Commonwealth parties not to take any steps to remove BXD18 and her family from Australia other than to a country that is a signatory to the Refugees Convention which has accepted her and her family for permanent settlement as refugees, until she has reached maximum medical improvement and provided that a psychiatric condition would not be at risk to again deteriorate. 143 For the most part, the Commonwealth parties' defence in BXD18's case was substantially the same as their defences in the Sydney cohort cases. The Commonwealth parties' defence included the further allegation (at [14A]) that: (a) … the standard of care pleaded is inconsistent with: (i) the duty in s 198AD of the [Migration] Act; (ii) the non-compellable nature of the power in s 198AE of the [Migration] Act; (iii) the discretionary and temporary nature of s 198B of the [Migration] Act; and (iv) the scheme of Subdivision B of Division 9 of Part 2 as a whole … . 144 Furthermore, at [27]-[28] of their defence the Commonwealth parties denied that BXD18 was entitled to the relief that she sought, on basis that the Court had no power to make a resettlement order and the proposed injunctive relief was inconsistent with the scheme of the Migration Act, particularly ss 189, 198B, 198AD, 198AE and 198AH. 145 In an amended reply filed on 9 April 2019, BXD18 said (at [1A]) that, "with particular reference to all pleas in the Respondents' defence of s 198AHA of the Migration Act": (a) from 25 March 2015, being the date that [BXD18], her father and her brother were determined to be refugees, there existed no purpose of processing or determining any protection claims of any of them; (b) as of 25 March 2015, the Commonwealth had not put in place any arrangement … for the permanent resettlement of any of [BXD18], her father, or her brother to a country other than Australia; (c) at all times, the Commonwealth's position has been that it would never permit the permanent resettlement in Australia of any person which it had taken to Nauru for the purpose of processing or determining that person's protection claims; and (d) in the premises, the power in s 198AHA of the Migration Act 1958 (Cth) ceased on 25 March 2015 to be available in respect of each and all of [BXD18], her father, and her brother. 146 The Commonwealth parties filed a rejoinder on 9 April 2019 in which they denied the substance of BXD18's reply and made further assertions about s 198AHA.

Applicant DIZ18 147 As already indicated, proceedings were begun for DIZ18 on 29 June 2018 while she was in PNG, with the filing of an originating application, an interlocutory application, supporting affidavits, and a statement of claim. An amended statement of claim was filed on 1 March 2019 and a defence on 19 March 2019. As in BXD18's case, there was a reply and rejoinder, filed on 2 April 2019 and 9 April 2019 respectively. 148 The allegations at [29]-[30] of the amended statement of claim in the case of DIZ18, which were set out under the heading "Duty of care, breach and injury", were as follows: [29] [DIZ18] (a very young child) and [DIZ18's] parents in Nauru: 29.1 had no ability to control whether; and 29.2 relied on the Commonwealth to ensure that [DIZ18] could receive an adequate and reasonable standard of medical care in an appropriate environment. [30] In the premises: 30.1 from at least when she was born, the Respondents have assumed responsibility for [DIZ18's] health and welfare; 30.2 at all relevant times, [DIZ18] has been dependent on the Respondents for the provision of medical treatment she might require, including dependent on them for receiving medical treatment of an adequate standard and where in the world it would be provided to her; 30.3 at all relevant times and continuing, the Respondents have owed [DIZ18] a duty of care to take all reasonable steps to procure for [DIZ18] a reasonable and adequate standard of medical treatment, to be provided in an appropriate environment. 149 The Particulars to [30] said: (i) The Respondents exercised effective and substantial control over, and assumed responsibility for, the medical treatment of [DIZ18] including the location of the medical treatment. (ii) Unless and until settled permanently as refugees in a country that will comply with the Refugees Convention not to discriminate against refugees including in the provision of medical care, the Mother and Father of [DIZ18] have no means, or ability to access medical treatment for [DIZ18], whether acute or ongoing, independent from that supplied or procured by the Respondents. (iii) [DIZ18] relied on the medical treatment, including diagnosis and limitations thereon, procured by the Respondents and which were initially only [to] be provided on Nauru. (iv) The Respondents exercised their control over [DIZ18] by determining to take her to PNG for medical treatment, given the limitation of the health services on Nauru. (v) By effectively and substantively controlling the medical treatment available to [DIZ18], the Respondents were in a position of power and responsibility over the future health outcomes of [DIZ18]. (vi) The Respondents knew or ought to have known that failure to procure adequate and reasonable medical treatment for [DIZ18] may cause harm to [DIZ18]. … 150 Previous paragraphs alleged facts and other matters of the same or a similar kind as those said to give rise to the alleged duty of care in the case of BXD18. DIZ18's amended statement of claim at [31] contained an analogous pleading with respect to the "relevant standard of care" as that in [14] of the statement of claim in the case of BXD18 (see [140] above). 151 The amended statement of claim in DIZ18's case (at [32]) alleged that the Commonwealth parties "acted negligently and in breach of the duty they owed" to DIZ18. In Particulars to [32] it was said: (i) Upon [DIZ18] becoming critically unwell, and in particular upon the receipt by the Respondent of the urgent medical advice on 12 June 2018, by failing to take all reasonable steps to urgently procure for [DIZ18] a reasonable standard of medical care, specifically treatment at a first world tertiary hospital with specialist intensive care services for paediatric patients. (ii) Taking [DIZ18] and the Mother to PNG for treatment at the PIH on 14 June 2018 in circumstances where: a. the PIH did not have the appropriate capabilities to treat [DIZ18] including but not limited to specialist intensive care services for paediatric patients, paediatric neurologist, ability to undertake paediatric MRI, or immediate capabilities to conduct a paediatric EEG. b. taking [DIZ18] to PNG was contrary to urgent medical advice at the time; c. the decision to take [DIZ18] to PNG was not made in consideration of her best medical interests, nor in the best interests of her as a child, and was in fact not in [DIZ18's] best medical interests; d. there was no medical justification for the decision to not take [DIZ18] to Australia. (iii) Prior to taking [DIZ18] to PNG, failing to make adequate enquiries about the medical care required by [DIZ18], including failing to refer [DIZ18's] medical circumstances to a Clinical Advisory Team at the Department to determine the standard of care required by [DIZ18]. (iv) Prior to taking [DIZ18] to PNG, failing to make adequate enquiries to ensure that the PIH had appropriate capabilities, facilities and expertise to treat [DIZ18]; (v) Causing and/or failing to prevent unreasonable delay in the treatment, diagnosis and rehabilitation of [DIZ18's] acute condition and any neurological sequelae. The amended statement of claim pleaded (at [33] and [34]) resulting loss and damage, including "[p]otential long term neurological deficits". 152 Besides damages, the relief sought included an "injunction requiring the Respondents to take and to continue to take all steps within their power to ensure that [DIZ18] receives treatment". 153 The defence filed by the Commonwealth parties on 19 March 2019 was substantially to the same effect as the defence that they had filed in the case of BXD18. The Commonwealth parties denied the existence of a duty of care and breach. They did not admit the alleged loss and damage, and they denied that DIZ18 was entitled to the relief sought. The Commonwealth parties' defence was followed by a reply filed on behalf of DIZ18, which in substance resembled the reply filed in the case of BXD18. That is, the reply in DIZ18's case also challenged the Commonwealth parties' reliance on the authority conferred by s 198AHA and alleged (at [11]) that "ss 198AD, 198AE and 198B and the 'scheme' as a whole of Subdiv B of Div 8 of Part 2 of the [Migration] Act, are incapable of applying to deny the duty [of] care, or to show inconsistency affecting the standard of care". A rejoinder filed on 9 April 2019 was in substance the same as the rejoinder filed in BXD18's case.

CONSTRUCTION OF SECTION 494AB 154 The resolution of this issue turns on the proper construction of relevant provisions in the Migration Act and then applying those provisions to the applicants' proceedings, when those proceedings are characterised as a matter of substance and not mere form. 155 The proper approach to contemporary statutory construction is well settled. It is reflected in the following observations of the plurality (Kiefel CJ, Nettle and Gordon JJ) in SZTAL v Minister for Immigration and Border Protection [2017] HCA 34; 262 CLR 362 at [14] (footnotes omitted): The starting point for the ascertainment of the meaning of a statutory provision is the text of the statute whilst, at the same time, regard is had to its context and purpose. Context should be regarded at this first stage and not at some later stage and it should be regarded in its widest sense. This is not to deny the importance of the natural and ordinary meaning of a word, namely how it is ordinarily understood in discourse, to the process of construction. Considerations of context and purpose simply recognise that, understood in its statutory, historical or other context, some other meaning of a word may be suggested, and so too, if its ordinary meaning is not consistent with the statutory purpose, that meaning must be rejected. 156 The difficulty lies not in identifying the relevant principles which guide statutory construction, but rather in their application.

(a) The legislative history concerning sections 494AB and 198AHA and related provisions 157 As noted above, context is an important consideration in statutory construction, including historical context. In brief, the legislative history relating to ss 494AB and 198AHA reveals the following. (a) Section 494AB in its original form was enacted in 2002, at the same time when the definition of a "transitory person" was inserted in s 5(1) and the power of an officer to bring a transitory person from outside Australia to Australia for a temporary purpose was introduced in s 198B of the Migration Act. (b) The mischief to which s 494AB was then directed was to ensure that a transitory person's presence in Australia was as short as possible and that, to that end, legal proceedings which could frustrate that objective should be barred, apart from proceedings in the High Court under s 75 of the Constitution. (c) It was not until 2012 that paragraph (ca) was inserted into s 494AB(1), at the same time when Subdiv B was inserted. Subdiv B deals with regional processing although, when it was originally enacted, it contained relatively few provisions relating to regional processing. They included the Minister's power to designate a country to be a "regional processing country" (s 198AB) and the duty of an officer to "take", as soon as reasonably practicable, an "offshore entry person" (as then defined in s 5(1)) from Australia to a regional processing country (s 198AD(2)). For the purposes of "taking" an offshore entry person from Australia to a regional processing country, various powers were conferred upon an officer under s 198AD(3), including placing such a person on a vehicle or vessel for that purpose and using such force as is necessary and reasonable. Subdivision B also included provisions which conferred on the Minister personally a non-compellable discretion to disapply the duty in s 198AD to take an offshore entry person to a regional processing country (s 198AE) and specified when the duty in s 198AD applies to a transitory person who is brought to Australia under s 198B (s 198AH). (d) It was not until 30 June 2015 that s 198AHA was inserted into Subdiv B, with retrospective effect to 18 August 2012 (ie when the original Subdiv B had commenced). 158 It is desirable to now expand upon the legislative history relating to the relationship between the bar imposed by s 494AB(1)(ca) and the operation of s 198AHA. The terms of those provisions are set out above at [8] and [14] and need not be repeated.

(i) The position in September 2001 159 The first thing to note is the legislative history relating to s 494AA, which also imposes a bar on certain proceedings concerning specified persons other than "transitory persons". When originally enacted in September 2001 by the Migration Amendment (Excision from Migration Zone) (Consequential Provisions) Act 2001 (Cth) (Excision Act), the bar in s 494AA operated by reference to certain legal proceedings concerning "offshore entry persons" as then defined in s 5(1) of the Migration Act. As originally enacted, s 494AA was in the following terms: 494AA Bar on certain legal proceedings relating to offshore entry persons (1) The following proceedings against the Commonwealth may not be instituted or continued in any court: (a) proceedings relating to an offshore entry by an offshore entry person; (b) proceedings relating to the status of an offshore entry person as an unlawful non‑citizen during any part of the ineligibility period; (c) proceedings relating to the lawfulness of the detention of an offshore entry person during the ineligibility period, being a detention based on the status of the person as an unlawful non‑citizen; (d) proceedings relating to the exercise of powers under section 198A. (2) This section has effect despite anything else in this Act or any other law. (3) Nothing in this section is intended to affect the jurisdiction of the High Court under section 75 of the Constitution. (4) In this section: Commonwealth includes: (a) an officer of the Commonwealth; and (b) any other person acting on behalf of the Commonwealth. ineligibility period means the period from the time of the offshore entry until the time when the person next ceases to be an unlawful non‑citizen. offshore entry means an entry into Australia that occurs: (a) at an excised offshore place; and (b) after the excision time for the offshore place concerned. 160 There are four things to note about the position in September 2001. First, the bar imposed by s 494AB had not yet been introduced, nor had the concept of a "transitory person". This did not occur until 2002 with the enactment of the Migration Legislation Amendment (Transitional Movement) Act 2002 (Cth) (Transitional Movement Act). 161 Secondly, the bar imposed by s 494AA operated in respect of four kinds of proceedings. It was not until 2012 that s 494AA(1) was amended so as to add a fifth kind of proceeding (as set out in paragraph (e) thereof), which barred "proceedings relating to the performance or exercise of a function, duty or power under Subdivision B of Division 8 of Part 2 in relation to an offshore entry person". At the same time, s 494AB(1) was amended by inserting into that provision a new paragraph (ca), which is in substantially similar terms to paragraph (e) of s 494AA(1), save that instead of referring to an "offshore entry person", paragraph (ca) refers to a "transitory person". 162 Thirdly, the concept of an "unauthorised maritime arrival" was substituted for the earlier concept of an "offshore entry person" in 2013 with the enactment of the Migration Amendment (Unauthorised Maritime Arrivals and Other Measures) Act 2013 (Cth). 163 Fourthly, the reference in s 494AA(1)(d) at that time to "proceedings relating to the exercise of powers under section 198A" is a reference to a provision which was also inserted into the Migration Act in 2001 by the Excision Act. Under s 198A(1) an officer was empowered to "take" an offshore entry person from Australia to a country in respect of which a Ministerial declaration was in force under s 198A(3). The officer's power under s 198A(1) was stated in s 198A(2) to include the power to do various things both within and outside Australia, including placing the person on a vehicle or vessel and using such force as is necessary and reasonable. It is to be noted that an officer's power to take a person to another country from Australia under s 198A(1) was discretionary and not mandatory. As will shortly emerge, this position changed in 2012 when s 198A was repealed and s 198AD was inserted. 164 It is desirable to say something more about the significance of the Transitional Movement Act, which introduced the concept of a "transitory person" in 2002.

(ii) The Transitional Movement Act (2002) 165 The following definition of "transitory person" was inserted by this Act into s 5(1) of the Migration Act: transitory person means: (a) an offshore entry person who was taken to another country under section 198A; or (b) a person who was taken to a place outside Australia under paragraph 245F(9)(b); or (c) a person who, while a non citizen and during the period from 27 August 2001 to 6 October 2001: (i) was transferred to the ship HMAS Manoora from the ship Aceng or the ship MV Tampa; and (ii) was then taken by HMAS Manoora to another country; and (iii) disembarked in that other country; but does not include a person who has been assessed to be a refugee for the purposes of the Refugees Convention as amended by the Refugees Protocol. 166 The Transitional Movement Act also introduced other important amendments, including: (a) severe restrictions on the capacity of a transitory person to apply for a visa while the person is in Australia (s 46A); (b) a non-compellable power of the Minister to waive those restrictions (ss 46A(2)-(7)); (c) s 198B was enacted, which empowered an officer, for a temporary purpose, to bring a transitory person to Australia from a country or place outside Australia. The power was defined as including the power to do various things both within or outside Australia, including placing the person on a vehicle or vessel and using such force as is reasonable and necessary; (d) in addition, s 198C was enacted, which created an entitlement for a transitory person who was brought to Australia under s 198B and who remained in Australia for a continuous period of six months to request the Refugee Review Tribunal to assess whether the person was a refugee within the meaning of the Refugees Convention. Under s 198C(8)(a), the Minister was obliged to determine a class of visa for the purposes of this provision; and (e) as noted above, the bar in s 494AB relating to the bringing of legal proceedings concerning transitory persons was introduced in its original form (ie not including what was later to become s 494AB(1)(ca)).

(iii) The 2012 amendments 167 Key relevant features of the amendments made to the Migration Act by the Migration Legislation Amendment (Regional Processing and Other Measures) Act 2012 (Cth) (Regional Processing Act) included the following: (a) Section 198A was repealed and replaced by Subdiv B, which is headed "Regional processing". The reason for Subdiv B was spelled out in s 198AA (see further at [169] below). Provision was also made for the Minister by legislative instrument to designate a country as a regional processing country (s 198AB). Section 198AD was also enacted. It obliged an officer, as soon as reasonably practicable, to take an offshore entry person who is detained under s 189 to a regional processing country. For that purpose, s 198AD(3) empowered an officer to do various things, both within or outside Australia, including placing an offshore entry person on a vehicle or vessel and using such force as is necessary and reasonable. (b) Subdivision C of Div 8 of Pt 2 was created for the first time. It is headed "Transitory persons etc.". Section 198B is one of the existing provisions which were brought into this subdivision. As noted above, it empowered an officer, for a temporary purpose, to bring a transitory person to Australia from a country or place outside Australia and also clarified the nature of that power. 168 Another point to emphasise is that when s 494AB(1)(ca) was first inserted in 2012 by the Regional Processing Act (together with the insertion of Subdiv B and the heading to Subdiv C, and the repeal of s 198A), the legislation did not contain any explicit provision concerning actions taken by the Commonwealth or its agents in relation to persons who had been taken to a RPC and were being detained there. Presumably, that was because the view was taken that the detention was based on the laws of the relevant regional processing country. As noted at 157 above, the provisions in Subdiv B were relatively confined. 169 We accept the applicants' submission that, as enacted, Subdiv B did not introduce a statutory scheme for the Commonwealth or its agents to exercise powers, perform functions or discharge duties in a regional processing country. Those matters were left to the law of the relevant regional processing country. This is substantially reflected in s 198AA of the Migration Act, which describes the reason for Subdiv B (as opposed to Subdiv C which deals with "transitory persons"). For convenience, the provision is set out again in full: 198AA Reason for Subdivision This Subdivision is enacted because the Parliament considers that: (a) people smuggling, and its undesirable consequences including the resulting loss of life at sea, are major regional problems that need to be addressed; and (b) unauthorised maritime arrivals, including unauthorised maritime arrivals in respect of whom Australia has or may have protection obligations under the Refugees Convention as amended by the Refugees Protocol, should be able to be taken to any country designated to be a regional processing country; and (c) it is a matter for the Minister and Parliament to decide which countries should be designated as regional processing countries; and (d) the designation of a country to be a regional processing country need not be determined by reference to the international obligations or domestic law of that country. It is notable that this provision makes no reference to the conferral of any duty, power or function on the Commonwealth or its agents in respect of actions taken in a regional processing country after an unauthorised maritime arrival has been removed from Australia and taken to such a country. 170 The further significant point to emphasise about the legislative history is the catalyst for the insertion of s 198AHA (on 30 June 2015, with retrospective effect to 18 August 2012) by the Migration Amendment (Regional Processing Arrangements) Act 2015 (Cth) (Regional Processing Arrangements Act). As noted above, s 198AHA was inserted in Subdiv B (and not Subdiv C which deals with "transitory persons"). The timing of the enactment is explained by litigation which was then pending in the High Court in Plaintiff M68/2015 v Minister for Immigration and Border Protection [2016] HCA 1; 257 CLR 42, the hearing of which commenced on 7 October 2015. The plaintiff in Plaintiff M68 alleged that the Commonwealth did not have any statutory authority to detain persons on Nauru or to fund their detention, relying for the latter contention on Williams v Commonwealth [2012] HCA 23; 248 CLR 156 (Williams (No 1)). Section 198AHA was enacted with the objective of providing the Commonwealth with statutory authority to fund and provide assistance to other countries in carrying out regional processing activities. This was recognised by Gageler J in Plaintiff M68 at [175] where his Honour said (emphasis added): The procurement of the plaintiff's detention on Nauru by the Executive Government of the Commonwealth under the Transfield contract was therefore beyond the executive power of the Commonwealth unless it was authorised by valid Commonwealth law. Before 30 June 2015, there was no applicable Commonwealth law. On that day, as has already been noted, s 198AHA was inserted with retrospective effect to 18 August 2012 … . 171 To similar effect, Keane J stated at [196] (emphasis added): … To the extent that the Commonwealth is said to have participated in the restraints upon the plaintiff's liberty in Nauru, the Minister and the Commonwealth contend that s 198AHA of the Migration Act affords such statutory authority as may be necessary to enable that action and to make any payments related to it. 172 These matters are confirmed by the Explanatory Memorandum which accompanied the Regional Processing Arrangements Act (2015 Explanatory Memorandum), as well as the Statement of Compatibility with Human Rights which was attached to that Explanatory Memorandum. 173 Relevantly, the 2015 Explanatory Memorandum stated that the Bill (emphasis added): … provides statutory authority for the Commonwealth to provide assistance to other countries to carry into effect arrangements for the processing and management of unauthorised maritime arrivals who have been taken to regional processing countries, including the expenditure of Commonwealth money on these arrangements … [and] confirms the ability of Australian officials, acting on behalf of the Commonwealth, to take action to assist the foreign government in the regional processing country, consistent with the law of that country. 174 It further stated that the amendments were given retrospective operation to (emphasis added): … put beyond doubt the Commonwealth's authority to take, or cause to be taken, actions in relation to regional processing arrangements or the regional processing functions of a country, and associated Commonwealth expenditure, from the date of commencement of the [Regional Processing Act]. The retrospective operation of these provisions will provide authority for all activity undertaken in relation to regional processing arrangements for the entire period these arrangements have been in place. 175 As regards s 198AHA, the 2015 Explanatory Memorandum stated that (emphasis added): The purpose of new subsection 198AHA(2) is to provide express statutory authority for the actions of the Commonwealth in relation to regional processing functions. It is intended that this would include the performance by the Commonwealth of an arrangement that the Commonwealth has entered into with a person or body in relation to the regional processing functions of a country. This provision is directed at ensuring that there is legislative authority to carry into effect arrangements for the processing and management of unauthorised maritime arrivals who have been taken to regional processing countries, and does not purport to have any effect in itself on the rights of those persons. The amendments in the Bill are consistent with the power provided in sections 198AB and 198AD of the Migration Act. The amendments authorise the Commonwealth to undertake action and expenditure to give effect to the regional processing arrangements authorised by those provisions. Subsection 198AHA(2) does not purport to provide the legal authority to detain a person taken to a regional processing country as any authority to exercise restraint over the liberty of a person arises under the law of the regional processing country. The purpose of subsection 198AHA(2) is merely to provide the Commonwealth with the express authority to carry into effect arrangements for supporting the processing and management of persons who have been taken to regional processing countries, consistent with the law of those countries. New subsection 198AHA(3) provides that, to avoid doubt, subsection 198AHA(2) is intended to ensure that the Commonwealth has capacity and authority to take action, without otherwise affecting the lawfulness of that action. 176 The Statement of Compatibility with Human Rights attached to the 2015 Explanatory Memorandum stated that (emphasis added): This Bill does not engage with the human rights and freedoms recognised or declared in the international instruments listed in section 3 of the Human Rights (Parliamentary Scrutiny) Act 2011, because the Government's view is that the Regional Processing Centres are managed and administered by the governments of the countries in which they are located, under the law of those countries. … The amendments made by this Bill strengthen and put beyond any doubt the existing legislative authority to give practical effect to the substantive regional processing provisions inserted by the [Regional Processing Act]. … Australia does not restrain the liberty of persons in regional processing countries. To the extent that the liberty of persons taken to regional processing countries is restrained in those countries, this is done under the laws of that country. The Bill confirms the ability of Australian officials, acting on behalf of the Commonwealth, to take action to assist the foreign government in the regional processing country. These amendments do not otherwise provide authority for any restraint over the liberty of persons. The lawful authority for any restraint over liberty arises under the law of the relevant regional processing country. The amendments in the Bill do not engage Australia's human rights obligations because the Government's position is that the … Regional Processing Centres are managed and administered by the governments of the countries in which they are located, under the law of those countries.

(b) General aspects of the construction of section 494AB 177 In light of the legislative history we have just canvassed and the terms of s 494AB it is not possible to discern one overarching purpose other than that, so far as constitutionally possible, certain proceedings are not to be instituted or continued except in the High Court. The effect of this is that, as stated in s 494AB(3), the jurisdiction of the High Court under s 75 of the Constitution is not affected. In practical terms, any proceedings which are barred by s 494AB may be commenced in the High Court. 178 Access to the courts generally is not removed but is limited as we have just explained. Contrary to the applicants' submissions, s 494AB is not a broad ouster clause: see O'Grady at 372. As the present litigation shows, however, the nature of the proceedings which are barred in the sense we have explained calls for closer examination. Since the jurisdiction of all courts other than the High Court is displaced in relation to the proceedings to which the bar applies, there is room for the application here of the "general proposition that a law of the Commonwealth is not to be interpreted as withdrawing or limiting a conferral of jurisdiction unless the implication appears clearly and unmistakably": see Shergold v Tanner [2002] HCA 19; 209 CLR 126 at [34] (footnote omitted). On the argument of the Commonwealth parties, not only is the jurisdiction in relation to those proceedings withdrawn from federal courts but also from State courts exercising federal jurisdiction, including in respect of actions in negligence against the Commonwealth. 179 In the task of statutory construction we have not been assisted by the consideration of the "inconvenience" of the specified proceedings being, in effect, required to be commenced in the High Court and, subject to s 44 of the Judiciary Act 1903 (Cth), heard and determined in that Court. No doubt the consequences of a particular interpretation may be taken into account: interpretation by reference to consequences is described as "essentially a shorthand version of the purposive approach to interpretation" by Pearce DC and Geddes RS, Statutory Interpretation in Australia (8th ed, LexisNexis Butterworths, 2014) at [2.39]. Nevertheless we would give those consequences little weight as they seem to us to amount to, at most, merely inconvenient or unsatisfactory consequences rather than consequences amounting to injustice or capriciousness or arbitrariness. We therefore do not need to consider the discussion of the question of remitter in DBE17 v Commonwealth [2018] FCA 1307; 361 ALR 423 at [130] and following. 180 It is to be noted that, contrary to the tenor of some of the submissions on behalf of the Commonwealth parties, s 494AB does not proceed by reference to "matters" as that word appears in Chapter III of the Constitution: rather, the relevant word is "proceedings" which appears in each of the paragraphs as well as in s 494AB(1). The cases have long drawn a distinction between those words: see, eg, Re Judiciary and Navigation Acts (1921) 29 CLR 257 at 265. This means, in our opinion, that the authorities relating to federal jurisdiction and in particular accrued jurisdiction are not directly applicable. We do not accept the "obvious parallel" contended for by the Commonwealth parties with reference to Moorgate Tobacco Co Ltd v Philip Morris Ltd [1980] HCA 32; 145 CLR 457 at 481 and Felton v Mulligan [1971] HCA 39; 124 CLR 367 at 373. Neither do we accept what appears to be a related submission by the Commonwealth parties that s 494AB(1)(a) applies because the applicants allege that the Commonwealth parties ought to have brought the applicants to Australia, and the Commonwealth parties contend that the source of power for doing so is s 198B. While that contention might well be sufficient to mean that the matter was in federal jurisdiction even if the Commonwealth was not a party, that does not necessarily mean that the present proceedings have the character referred to in s 494AB(1)(a). 181 In our opinion, s 494AB requires a characterisation of the proceedings as a matter of substance rather than form, and that character will commonly be discerned at the institution of the proceedings. 182 In that respect we note that we do not accept the submission on behalf of the Melbourne cohort that the word "continued" in the expression in s 494AB(1) "may not be instituted or continued in any court" is limited to proceedings which were commenced before the introduction of s 494AB into the Migration Act. We reject that submission because it would be an unusual place to find a transitional provision and, in our view, the word has work to do in applying to proceedings which are maintained in any court other than the High Court, including such proceedings which by amendment take on the character of proceedings barred by s 494AB. We understand that in DBE17 at [61], in relation to the same wording in s 494AA(1), Mortimer J said that the chronology of the Tampa incident, and the litigation surrounding it, informed why it was important that s 494AA included the "continuation" of proceedings. But we would not accept what may be implicit in her Honour's statement that the "continuation" limb applied only to proceedings which were commenced before the introduction of the section. We accept that in s 494AB the words "or continued" would apply to proceedings pending when the section was introduced, but we do not consider that that language is so limited. As we have said, in our view the language extends to proceedings which take on the character of any of the barred proceedings after the proceedings have been commenced. 183 In each of the three paragraphs in s 494AB(1) on which the Commonwealth parties relied, the words "relating to" are used to describe, in part, the character of the proceedings to which the bar applies. We accept the submission on behalf of the Commonwealth parties that "relating to" is a broad expression but that tells the reader very little about the kinds of relationship which the paragraphs envisage. This is a question of statutory construction, well explained, with respect, by French CJ and Hayne J in Travelex Ltd v Commissioner of Taxation [2010] HCA 33; 241 CLR 510 at [25] (footnotes omitted): It may readily be accepted that "in relation to" is a phrase that can be used in a variety of contexts, in which the degree of connection that must be shown between the two subject matters joined by the expression may differ. It may also be accepted that "the subject matter of the inquiry, the legislative history, and the facts of the case" are all matters that will bear upon the judgment of what relationship must be shown in order to conclude that there is a supply "in relation to" rights. In that case the relevant question was whether selling foreign currency on the departure side of the Customs barrier at Sydney International Airport to a traveller who intends to use the currency overseas was a supply made "in relation to rights" within item 4 in the table in s 38-190(1) of A New Tax System (Goods and Services Tax) Act 1999 (Cth). Contrary to the submissions on behalf of the applicants, we do not derive any specific assistance from the decision in Perlman v Perlman [1984] HCA 4; 155 CLR 474, where it was held that proceedings commenced in the Supreme Court of New South Wales to enforce a maintenance agreement did not fall within the definition of "matrimonial cause" and were therefore not outside the jurisdiction of the Supreme Court. Those proceedings were held not to be "proceedings … in relation to concurrent, pending or completed proceedings of a kind referred to" in the preceding paragraphs of the definition of "matrimonial cause" as defined in s 4(1) of the Family Law Act 1975 (Cth), those earlier proceedings being proceedings in which the Family Court of Australia approved the agreement. 184 The task is one of statutory construction. In that task it is significant that in the first of the paragraphs relied on by the Commonwealth parties, s 494AB(1)(a), the proceedings are those relating "to the exercise of powers" (emphasis added) under section 198B. In the second of the paragraphs so relied on, s 494AB(1)(ca), the proceedings are those relating "to the performance or exercise of a function, duty or power" (emphasis added) under Subdiv B of Div 8 of Pt 2. In the third of those paragraphs, s 494AB(1)(d), the proceedings are those relating "to the removal of a transitory person from Australia under the Act" (emphasis added). As will become apparent, the emphasised aspects of the language of ss 494AB(1)(a), (ca) and (d) shed light on the sort of relationship required to be shown between a proceeding and the relevant provisions of the Migration Act in order to conclude that the proceeding has the relevant character. 185 The applicants submitted that the scope of the three relevant paragraphs of s 494AB(1) may be limited to proceedings challenging the exercise of the relevant statutory power or powers, or the assertion of a duty to exercise that statutory power or powers, or a proceeding to enforce the performance of a relevant duty. As will be seen, we do not proceed on that basis. We have approached the issue without construing the provisions to contain unexpressed limitations, while accepting that what the applicants submitted is one example of, but does not exhaust, what is covered by the words of exclusion.

DOES THE BAR IN SECTION 494AB(1)(CA) APPLY TO ANY OF THE PROCEEDINGS?

(a) No intersection between sections 494AB(1)(ca) and 198AHA 186 The distinction between powers and capacities is one which has a long history in the law relating to public executive action. The distinction is both sufficiently and clearly explained by Gageler J in Plaintiff M68 at [132] and [134]-[135] (footnotes omitted and noting that the reference to Brennan J is a reference to his Honour's reasons for judgment in Davis v Commonwealth [1988] HCA 63; 166 CLR 79 at 108): Put in terms of [Professor Winterton's nomenclature, distinguishing between the "breadth" and "depth" of Commonwealth executive power], Brennan J referred exclusively to the depth of Commonwealth executive power when he noted that "an act done in execution of an executive power of the Commonwealth is done in execution of one of three categories of powers or capacities: a statutory (non-prerogative) power or capacity, a prerogative (non-statutory) power or capacity, or a capacity which is neither a statutory nor a prerogative capacity". … The tripartite categorisation posited by Brennan J has utility in highlighting, in relation to acts done in the exercise of a non-statutory power or capacity, the essential difference between an act done in the execution of a prerogative executive power and an act done in the execution of a non-prerogative executive capacity. An act done in the execution of a prerogative executive power is an act which is capable of interfering with legal rights of others. An act done in the execution of a non-prerogative executive capacity, in contrast, involves nothing more than the utilisation of a bare capacity or permission, which can also be described as ability to act or as a "faculty". Such effects as the act might have on legal rights or juridical relations result not from the act being uniquely that of the Executive Government but from the application to the act of the same substantive law as would be applicable in respect of the act had it been done by any other actor. In this respect, the Executive Government "is affected by the condition of the general law". Subject to statute, and to the limited extent to which the operation of the common law accommodates to the continued existence of "those rights and capacities which the King enjoys alone" and which are therefore properly to be categorised as prerogative, the Executive Government must take the civil and criminal law as the Executive Government finds it, and must suffer the civil and criminal consequences of any breach. 187 Although Gageler J was there referring to the essential difference between non-statutory prerogative powers and non-statutory non-prerogative capacities, that essential difference applies equally in respect of statutory powers and statutory non-prerogative capacities. Whereas a statutory power is capable of interfering with legal rights, a statutory capacity does no more than confer a bare capacity, permission or faculty to engage in conduct, in the exercise of which the executive must "take the civil and criminal law as [it] finds it, and must suffer the civil and criminal consequences of any breach". Whether s 198AHA(2) confers a power or merely a capacity to engage in the relevant conduct is, of course, a question of statutory construction. 188 As to that question of construction, it is tolerably clear from his Honour's reasons in Plaintiff M68, particularly at [181], that Gageler J regarded s 198AHA(2) as limited to conferring statutory capacity on the Commonwealth (emphasis added): Section 198AHA(3) is important in clarifying that s 198AHA(2) is directed to nothing other than ensuring that the Commonwealth has capacity and authority to take action and that it does not otherwise affect the lawfulness of that action. That is to say, s 198AHA(2) is directed to nothing other than conferring statutory capacity or authority on the Executive Government to undertake action which is or might be beyond the executive power of the Commonwealth in the absence of statutory authority. The section has no effect on the civil or criminal liability of the Executive Government or its officers or agents under Australian law or under the law of a foreign country. The lawfulness or unlawfulness of Executive Government action under Australian law or under the law of a foreign country conversely does not determine whether or not that action falls within the scope of the statutory capacity or authority conferred by the section. 189 Consistently with this understanding of his Honour's reasons, in explaining why principles derived from Chu Kheng Lim v Minister for Immigration, Local Government and Ethnic Affairs [1992] HCA 64; 176 CLR 1 are applicable to s 198AHA, Gageler J noted at [184] that he could "see no principled reason to distinguish between a law which confers a power of executive detention and a law which confers a capacity for executive detention so as to allow for the exercise of power from another legislative source." The reference to another legislative source presumably captures laws of the regional processing country mentioned in s 198AHA(1) that empower the Commonwealth or its officers to undertake acts in relation to which s 198AHA(2) confers capacity. 190 The Commonwealth parties submitted that Gageler J's reasons in Plaintiff M68 at [181], and in particular his general observation that s 198AHA "has no effect on the civil or criminal liability", should "be approached with some caution" because, so it was submitted, s 198AHA "can truly affect the lawfulness of an action". Indeed, the Commonwealth parties submitted that it did so in Plaintiff M68 because, on Gageler J's reasoning, the plaintiff's detention would otherwise have been unlawful (and presumably compensable in damages). However, the trite observation that capacity is a necessary ingredient of the validity (in a public law sense) of governmental action, which may be of decisive importance in, for instance, a false imprisonment claim, should not distract from what is presently relevant, which is that s 198AHA confers a capacity or authority, as distinct from a power, to engage in the relevant conduct to which it applies, in the exercise of which the Commonwealth takes the civil and criminal law as it finds it. 191 The passage of Gageler J's reasons in Plaintiff M68 at [181] extracted above was unanimously adopted in Plaintiff S195/2016 v Minister for Immigration and Border Protection [2017] HCA 31; 261 CLR 622 at [27]. It is also consistent with the plurality's reasons in Plaintiff M68. Relevantly, the plurality held there that the plaintiff was "detained in custody under the laws of Nauru" (at [32]) and that "the restrictions applied to the plaintiff are to be regarded as the independent exercise of sovereign legislative and executive power by Nauru" (at [34]), from which it followed that "the Commonwealth did not itself detain the plaintiff" (at [36]). Put another way, s 198AHA(2) did not provide the source of legislative power under which the plaintiff was detained: Nauruan law did. Although, in determining whether the Commonwealth's participation in the plaintiff's detention was supported by s 198AHA, the plurality subsequently referred (at [46]) to that provision ensuring the Commonwealth has "power to fund the [Regional Processing] Centre and the other services to be provided under these arrangements" (emphasis added), properly understood their Honours were referring to the Commonwealth's capacity to spend which, absent legislative authority, has been regarded as limited after Williams (No 1). This understanding is confirmed by the statement in the very next sentence of the plurality's reasons in Plaintiff M68, that "the authority in [s 198AHA(2)] would extend to permitting the Commonwealth to provide services to carry into effect the laws of Nauru" (emphasis added). Again, this reflects an understanding of s 198AHA as conferring a capacity or bare authority, with Nauruan law supplying any power or constraints on the performance of relevant activities on Nauru in respect of persons who have been taken there under Australia's regional processing arrangements. 192 Even were the matter free from authority, we would reach the same conclusion as a matter of ordinary statutory construction. The text of s 198AHA supports such a conclusion. That the authority conferred by s 198AHA(2) has the "inherent character" which distinguishes a capacity from a power (namely that its exercise is subject to the law and does not itself affect rights and liabilities: see Plaintiff M68 at [135]-[136] per Gageler J) is explicitly stated by the terms of s 198AHA(3). They provide that "[t]o avoid doubt, subsection (2) is intended to ensure that the Commonwealth has capacity and authority to take action, without otherwise affecting the lawfulness of that action" (emphasis added). It is also significant that s 198AHA(3) uses the language of "capacity and authority", rather than "power", to describe the operation of s 198AHA(2). The reference in the heading to s 198AHA to "power" cannot displace the actual language used in the operative parts of the provision even though the heading is a relevant aid to statutory construction: H v Minister for Immigration and Citizenship [2010] FCAFC 119; 188 FCR 393 at [72]. 193 As mentioned above, relevant extrinsic materials support this construction. The 2015 Explanatory Memorandum states that s 198AHA(2) "does not purport to have any effect in itself on the rights of" people in the position of the applicants. The Statement of Compatibility with Human Rights attached to the 2015 Explanatory Memorandum similarly states that "[t]o the extent that the liberty of persons taken to regional processing countries is restrained in those countries, this is done under the laws of that country"; that s 198AHA(2) "confirms the ability of Australian officials … to take action to assist the foreign government in the regional processing country"; and that s 198AHA does "not otherwise provide authority for any restraint over the liberty of persons." Any tension between the last statement and the explicit inclusion by s 198AHA(5) of "exercising restraint over the liberty of a person" in the "action" authorised by s 198AHA(2) is resolved by reading "otherwise" in the Explanatory Memorandum as meaning otherwise than as provided by the relevant foreign country's laws. These statements are significant for two reasons. First, they confirm that s 198AHA(2) confers a statutory capacity only, and does not provide a source of power (capable of interfering with rights) to engage in the relevant activities. Secondly, they demonstrate that it was not contemplated that the inclusion of s 198AHA within Subdiv B would have the effect, by operation of s 494AB(1)(ca), of preventing litigants from instituting or continuing proceedings in courts (at least other than the High Court) which might be thought to constitute an "effect … on the rights of" people in the applicants' position. 194 Once it is appreciated that the "capacity and authority" conferred by s 198AHA(2) is limited to a statutory capacity (to adopt Brennan J's nomenclature in Davis at 108), or bare authority or permission, or faculty, to engage in certain activities, it follows that an exercise of that capacity cannot constitute "the performance or exercise of a function, duty or power under Subdivision B of Division 8 of Part 2 in relation to a transitory person". This is so for two primary reasons. 195 First, it is difficult to read the compound expression "function, duty or power" as encompassing a statutory capacity. As explained above a capacity, by its very nature, is to be distinguished from a power. Similarly, "function" implies a statutorily mandated responsibility, task or object, and "duty" implies a positive obligation; neither naturally describes the operation of a statutory capacity. 196 Secondly, and perhaps more significantly, even if the phrase is read distributively and "performance … of a function", or any other permutation, given a broad meaning which encompasses the exercise of a statutory capacity conferred by s 198AHA, any such exercise would not constitute the "performance or exercise of a function, duty or power under" the relevant subdivision of the Migration Act. In Griffith University v Tang [2005] HCA 7; 221 CLR 99, the plurality of the High Court (Gummow, Callinan and Heydon JJ) observed at [29] that the adoption of the statutory language "decision of an administrative character made … under an enactment" directed attention "to the source of the power of the decision-makers." That is the natural way in which one reads "under" in s 494AB(1)(ca). In explicating what relationship between a "decision of an administrative character" and a relevant "enactment" was entailed by that statutory language in its context, the plurality in Tang rhetorically asked at [80]: "does the decision in question derive from the enactment the capacity to affect legal rights and obligations?" The plurality held, at [81], that "[i]f the decision derives its capacity to bind from contract or some other private law source, then the decision is not 'made under' the enactment in question". At [82], the plurality stated: For these reasons, a statutory grant of a bare capacity to contract does not suffice to endow subsequent contracts with the character of having been made under that enactment. A legislative grant of capacity to contract to a statutory body will not, without more, be sufficient to empower that body unilaterally to affect the rights or liabilities of any other party. The power to affect the other party's rights and obligations will be derived not from the enactment but from such agreement as has been made between the parties. A decision to enter into a contract would have no legal effect without the consent of the other party; the agreement between the parties is the origin of the rights and liabilities as between the parties. See also, to similar effect, at [18] per Gleeson CJ. 197 The plurality's conclusion in Tang in relation to the phrase "under an enactment" was influenced by the subject matter of the relevant statutory expression being "administrative decisions". Their Honours regarded it as relevant to inquire at [79] into "[w]hat is it, in the course of administration, that flows from or arises out of the decision taken so as to give that significance which has merited the legislative conferral of a right of judicial review", which they identified in "general terms" at [80] as "the affecting of legal rights and obligations". The same answer should be given, in the legislative context relevant here, to the question what is it that flows from or arises out of the exercise of a relevant "function, duty or power" - significantly, in relation to a transitory person - which establishes the sort of relationship with a proceeding that merits the legislative exclusion of that proceeding by s 494AB(1)(ca) from those which can be instituted or continued in courts other than the High Court. Proceedings of the kind contemplated by s 494AB(1) involve, at their core, an exercise of judicial power to resolve contested rights and liabilities, and the character of those proceedings derives from what rights and liabilities are sought to be so determined. Properly construed, therefore, a proceeding is related to the exercise of a function, duty or power under the relevant subdivision of the Migration Act only if that subdivision gives to the relevant performance or exercise of a function, duty or power in relation to a transitory person the capacity to affect the rights of the transitory person which are sought to be determined in the proceeding. 198 As explained above, s 198AHA(2) does not give to the actions to which it relates the ability to interfere with the rights of transitory persons, because it is not a source of power to engage in those actions. Any actions alleged in the present case which constitute an exercise of the capacity conferred by that section are not, therefore, to be regarded as "under" the Migration Act, or any part of it, for the purposes of s 494AB(1)(ca). To the extent any of those actions are to be regarded as "under" anything, in the sense of that thing giving to the Commonwealth government a source of power to engage in the activities and giving that engagement the capacity to interfere with rights, they could be regarded as being under applicable laws of Nauru or an applicable aspect of the non-statutory executive power. 199 Section 198AHA does not confer any statutory powers, duties or functions on the Commonwealth, but rather confers a bare capacity that enables the Commonwealth to be conferred with powers or functions or duties under the laws of a regional processing country. 200 As the Commonwealth parties pointed out, in the task of statutory construction a statute which is amended and an amending statute are to be read together as a combined statement of the will of the legislature (see Commissioner of Stamps (SA) at 463, Seller at [100] and s 11B(1) of the Acts Interpretation Act 1901 (Cth)). The Commonwealth parties submitted that s 494AB had to be construed in the light of the 2015 amendment which inserted s 198AHA, retrospective to 18 August 2012. Those submissions should be accepted. 201 That acceptance does not, however, change the nature of the interaction between ss 494AB(1)(ca) and 198AHA. For the above reasons, as a matter of statutory construction, the capacity or authority conferred by s 198AHA(2) does not intersect with s 494AB(1)(ca) in any manner relevant to the present proceedings. 202 The Melbourne cohort also submitted, in the alternative, that s 198AHA does not apply to persons such as them who have already been determined to be refugees. It is unnecessary to determine this alternative contention having regard to our reasoning and conclusion above.

(b) The applicants' proceedings with reference to section 494AB(1)(ca) 203 Against the background of what we have said above regarding the absence of any intersection, as a matter of statutory construction, between ss 494AB(1)(ca) and 198AHA, it is convenient to now address each of the applicants' proceedings to determine whether the bar in s 494AB(1)(ca) applies. In conducting this exercise, we have noted the Commonwealth parties' alternative constructions of s 494AB and each of its limbs, including that in s 494AB(1)(ca). The first, and broader, suggested construction is that the bar in s 494AB is engaged if the determination of the factual and legal issues raised in a proceeding involve an analysis, or close analysis, of the terms of relevant provisions of the Migration Act. The alternative, and narrower, suggested construction is that the bar in s 494AB is engaged if the rights and liabilities asserted by an applicant depend on their consistency with the relevant statutory provisions or scheme. A related contention advanced by the Commonwealth parties is that s 494AB is intended to capture "tort-based proceedings" concerning the exercise or non-exercise of regional processing powers, functions or duties. 204 It may be accepted that, at a level of principle, the bar in s 494AB(1)(ca) could operate in respect of some tort-based proceedings. One example is a proceeding in which damages are sought against the Commonwealth for breach of a statutory duty under Subdiv B in relation to a transitory person. As Gummow J stated in Pyrenees Shire Council v Day [1998] HCA 3; 192 CLR 330 at [124], negligence has "a doctrinal basis" which differs from an action for breach of statutory duty. Whether or not a particular statute gives rise to a cause of action for breach of statutory duty rests upon legislative intention. An action lies for damages for breach of statutory duty "where a statute which imposes an obligation for the protection or benefit of a particular class of persons is, upon its proper construction, intended to provide a ground of civil liability when the breach of the obligation causes injury or damage of a kind against which the statute was designed to afford protection": Byrne v Australian Airlines Ltd [1995] HCA 24; 185 CLR 410 at 424 per Brennan CJ, Dawson and Toohey JJ. In such a case, the rights sought to be determined in the proceeding can fairly be said to arise from the statute. In Australian jurisdictions, liability for breach of such a duty may also turn upon questions which are closely related to those which arise in considering the legality (in a public law sense) of an act or omission said to breach the statutory duty. There is little difficulty in describing an action for damages for breach of statutory duty as a proceeding relating to the performance of a duty under the relevant statute. 205 None of the four proceedings here pleads any such breach of statutory duty. Rather, each of the applicants pleads that they are owed a common law duty of care by the Commonwealth, the breach of which entitles them to damages. The source of such a duty is not statute, but the common law. As Gibbs CJ observed in Heyman at 434 (which concerned a common law duty said to be owed by a statutory authority): The respondents' action is founded on negligence, and not on breach of statutory duty, and the statutory provisions to which reference has been made are relied on not as the source of the Council's obligations, but as the setting in which its acts and omissions have to be considered. 206 Whether or not a statute validly authorised or required the relevant act does not bear directly upon the liability of the statutory authority pursuant to a common law duty. As McHugh J succinctly stated in Crimmins at [82], "[o]n the current state of the authorities, the negligent exercise of a statutory power is not immune from liability simply because it was within power, nor is it actionable in negligence simply because it is ultra vires". As the High Court explained in Howard v Jarvis at 183 (a case relied upon by the Sydney cohort) (emphasis in original): … Howard was subject at common law to a duty to exercise reasonable care for the safety of Jarvis during his detention in custody. … In arresting and detaining Jarvis he was no doubt acting lawfully and properly and in the due execution of his duty, but he was depriving Jarvis of his liberty, and he was assuming control for the time being of his person, and it necessarily followed, in our opinion, that he came under a duty to exercise reasonable care for the safety of his person during the detention. 207 On its proper construction, s 494AB(1)(ca) requires more than that acts are pleaded which constitute, or are claimed to constitute, a valid exercise or performance of a relevant function, duty or power. The proposition that the pleaded acts were authorised should, at least, have some direct legal consequence in the case. Or, to put it another way, the rights and duties sought to be determined in the proceedings should arise from the conferral or imposition by the Migration Act of the relevant powers, functions or duties, through the medium of their exercise or performance. Again this reflects the attention given by the statutory text to both the phrase "performance or exercise of functions, duties or powers" in respect of a transitory person, and to the need for that performance or exercise to be "under" the relevant part of the Migration Act, which directs attention to whether the Migration Act is the legal source of any effect of a relevant performance or exercise on the rights sought to be determined in the proceedings, as explored above. 208 So construed, s 494AB(1)(ca) is not engaged in the context of a negligence action founded, as is the case here for each of the four proceedings, upon an alleged common law duty merely because some of the facts said to give rise to a duty are claimed to be authorised by ss 198AB or 198AD. Such a duty, whether novel or within a recognised category, arises under the common law by reason of the relationship in fact existing between an applicant and a respondent. The incidents or salient features of that relationship are ascertained at the level of fact, without regard to whether the conduct disclosed by those facts is, as a matter of law, authorised by statute. To adopt the language of Barwick CJ in Birch at 659, on the applicants' case, "there was … a duty at common law resting on the respondent, unconnected with its statutory authority, or any duty derived from its constating statute" which "derived from the fact and circumstances" of the case. 209 The rights or duties sought to be determined in these four proceedings arise from the common law, unconnected with the performance or exercise of any statutory function, duty or power. Accordingly, the proceedings are not proceedings relating to any such performance or exercise. 210 Of course, that is not to say that statutory provisions are irrelevant in a proceeding brought against a statutory authority for breach of a common law duty of care. As McHugh J stated in Crimmins at [114] "[n]o common law duty of care can be imposed on a statutory authority if to do so is either forbidden by the relevant Act or is inconsistent with the statutory scheme", not the least because coherence of the law must be preserved. Accordingly, in such a case, close attention has to be paid to relevant statutory provisions (see, for example, Pyrenees Shire Council at [126] (Gummow J); Sullivan v Moody at [50] and [55] (Gleeson CJ, Gaudron, McHugh, Hayne and Callinan JJ); Leichardt Municipal Council v Montgomery [2007] HCA 6; 230 CLR 22 at [137] (Hayne J); CAL No 14 Pty Ltd v Motor Accidents Insurance Board [2009] HCA 47; 239 CLR 390 at [41] (Gummow, Heydon and Crennan JJ)). Such attention may be particularly important where the statute "establishes relationships, conduct or other subject matter which are not previously known to the common law and whose origins lie wholly within the four walls of the statute": Crimmins at [159] (Gummow J). In a case founded upon a common law duty, however, the source of a statutory authority's alleged liability is the common law, with the statutory provisions providing the "setting in which its acts and omission have to be considered": Heyman at 434 (Gibbs CJ); and see also Crimmins at [25] (Gaudron J), [154] and [157] (Gummow J); Birch at 658-659 (Barwick CJ); Graham Barclay Oysters at [80] (McHugh J). 211 Senior counsel for the Commonwealth parties made repeated reference to a duty of care being inconsistent with the "scheme" created by the regional processing legislation, including the specific provisions to which s 494AB is directed. The Commonwealth parties' submissions, particularly in reply, emphasised the important role of statute in negligence cases against public authorities. 212 The major premise underlying both the broad and narrow constructions of the Commonwealth parties is that it is sufficient to characterise the proceedings as relating to the performance or exercise of a function, duty or power under the provisions to which ss 494AB(1)(a) and (ca) refer, that a Court would need to determine the applicants' common law negligence claims consistently with, and against the background of, those provisions. 213 That contention should be rejected. It pays insufficient attention to the statutory language. Importantly, for a proceeding to be captured by ss 494AB(1)(a) or (ca), it must be a proceeding relating to the "exercise of powers under" or "performance or exercise of a function, duty or power under" the nominated provision. Coherence reasoning, of the kind fixed upon by the narrow construction, promotes coherence of the entire body of law between the enacted provisions of legislation and the common law of negligence. The requirement that attention be given to relevant statutes fixed upon by the broader construction ensures that statutory schemes and enabling legislation are considered as relevant context and background in applying the common law of negligence. In either case, it is the terms of the legislation, and often also the policy which stands behind them, which are relevant: see, eg, Birch at 658 (Barwick CJ); Graham Barclay Oysters at [78] (McHugh J); and Crimmins at [27] (Gaudron J), [159] (Gummow J). Critically, neither form of reasoning depends on or gives any significance to whether the statutory powers or duties which are said to give rise to the inconsistency are, in respect of any particular applicant, exercised or performed. 214 This is not to understate the potentially significant and decisive role that statute can play in a proceeding involving a common law negligence claim. Rather, it is to recognise that that role does not give such a proceeding the character described by the terms of s 494AB(1)(ca) (or, for that matter, paragraph (a) of that provision). To accept the Commonwealth parties' contention would involve impermissibly reading ss 494AB(1)(a) and (ca) as if they were directed to "proceedings relating to … section 198B" and "proceedings relating to … Subdivision B of Division 8 of Part 2" and give the excised words from those provisions no work to do. It would have been a simple matter for the Parliament to have enacted a provision barring the commencement or maintenance by a transitory person of all such proceedings against the Commonwealth, "relating to … section 198B" or " relating to … Subdivision B of Division 8 of Part 2", except in the High Court, if that had been intended. 215 There is a further difficulty with the Commonwealth parties' position. It is not obvious that the minor premise of this aspect of their argument will be made out at trial. Although not raised at this jurisdictional stage by the applicants, and it not being the subject of argument before the Full Court, it may be open to the applicants to contend, and for a trial judge to find, that the applicable law governing issues of substance in the applicants' negligence claims, including any duty of care, is the law of Nauru. It is not clear what, if any, attention would then need to be given to the provisions of the Migration Act to which s 494AB is directed in determining, as a matter of Nauruan law, the existence or extent of any common law duty of care. The basis for any relevant requirement for coherence (between the common law of Nauru, as modified by Nauruan statutes, and the Migration Act) has not been articulated by the Commonwealth parties. 216 Our approach does not deplete s 494AB(1)(ca) of any meaningful operation. Rather, the bar imposed by s 494AB(1)(ca) operates, for example, to require the following kinds of proceedings against the Commonwealth relating to a transitory person to be brought in the High Court and not in any other court (unless, perhaps, remitted): (a) proceedings based on an alleged breach of relevant statutory duty (as it is the duty which itself gives rise to the rights to be determined); (b) proceedings which have as an element that the Commonwealth or its officers acted beyond power, such as misfeasance in public office based on a purported exercise or performance of a relevant function, duty or power (where the invalidity of a purported exercise or performance of a function, duty or power gives rise to the rights sought to be determined in the proceeding); and (c) judicial review proceedings concerning the lawfulness of the exercise or performance of a relevant function, duty or power (for essentially the same reason as for (b)). These examples are not intended to be exhaustive, but indicative only. 217 It is convenient to now apply the general principles discussed above to each of the four proceedings here with reference to the applicants' pleaded cases and the Commonwealth parties' contention that each is barred by s 494AB(1)(ca).

Applicant FRM17's proceeding 218 In FRM17's proceeding, the pleaded case is in common law negligence. Although FRM17's FASC contains numerous references to the Commonwealth parties exercising powers "under s 198AHA of the Act and/or s 61 of the Constitution" in relation to things that happened to FRM17 on Nauru to which the pleaded duty of care applies, the reference to powers under s 198AHA is properly understood as a reference to the capacities of the Commonwealth, consistently with its proper construction. 219 The references to s 61 of the Constitution as an alternative source of authority for the actions and/or omissions of the Commonwealth parties on Nauru in relation to FRM17 does not attract the bar in s 494AB(1)(ca). That is simply because, in its own terms, that bar is limited to proceedings relating to the performance or exercise of a function, duty or power under Subdiv B in relation to a transitory person, and not to the performance or exercise of a function, duty or power sourced in s 61 of the Constitution in relation to a transitory person. 220 Similarly, there is no inconsistency or incompatibility between the pleaded duty of care owed by the Commonwealth parties to FRM17 in respect of her time on Nauru and the statutory duty contained in s 198AD(2) of the Migration Act. The duty of an officer under that provision to take, as soon as reasonably practicable, an unauthorised maritime arrival to whom the section applies from Australia to a regional processing country says nothing about any common law duty of care which is owed by the Commonwealth in respect of such a person after they are taken to the regional processing country. 221 Nor is there any inconsistency or incompatibility with the pleaded duty of care owed by the Commonwealth parties to FRM17 in respect of her time on Nauru and the purpose of Subdiv B. That purpose, as reflected in s 198AA and other provisions in that subdivision, has nothing to say about duties of care owed by the Commonwealth to persons who have been taken to a regional processing country in relation to acts or omissions which affect such persons there. The only exception is s 198AHA but, on its proper construction, it provides no support to this aspect of the Commonwealth parties' defence. 222 Accordingly, for these reasons, the bar in s 494AB(1)(ca) does not apply to FRM17's pleaded case in negligence. 223 In their amended defence in respect of FRM17, the Commonwealth parties contended that s 494AB(1)(ca) applies because "the existence of the alleged duty of care, and the alleged liability for damages and other relief claimed, are matters which depend significantly upon the application and effect of provisions" in Subdiv B (emphasis added). 224 We have explained above why we consider that s 494AB(1)(ca) does not apply to FRM17's claim for damages based on her common law claim in negligence. We do not consider that the bar in s 494AB(1)(ca) applies to the injunctive relief sought by FRM17 in her originating application, her interlocutory application or in FRM17's FASC. That is because none of those claims for injunctive relief, whether interim or permanent, related to the performance or exercise of a function, duty or power under Subdiv B. Although FRM17 initially sought an interim injunction restraining the Commonwealth parties from detaining her on Nauru or any other offshore processing centre, this claim was not expressed by reference to any function, duty or power under Subdiv B. Further, as foreshadowed above, FRM17 was not seeking to prevent her removal from Australia where the statutory duty to remove arose under s 198AD(2); rather she was seeking appropriate medical treatment wherever it might be obtained. The same can be said concerning the interim injunction sought by FRM17 to restrain the Commonwealth parties from not permitting her to travel to another country to obtain urgent psychiatric medical attention. Thus the bar in s 494AB(1)(ca) did not prevent the institution of the proceedings by FRM17. For much the same reasons, it did not prevent the continuation of the proceedings on the amended pleadings, even before FRM17 abandoned her claim for a permanent injunction. Further, as will be seen, no issue arises in FRM17's proceeding with respect to ss 494AB(1)(a) or (d).

Applicant DLZ18's proceeding 225 DLZ18's pleaded case is also in common law negligence. The relevant paragraphs of the statement of claim relating to the pleaded common law duty of care owed by the Commonwealth parties to DLZ18 while she was detained on Nauru, and the breach of that duty of care, make no express or implicit reference to any of the statutory provisions in Subdiv B. Even if, as pleaded by the Commonwealth parties in their defence, the relevant parts of the statement of claim were read as alleging a breach of duties of care as a result of actions taken, or omitted to have been taken, under s 198AHA, this is insufficient to attract the bar when regard is had to the proper construction of that provision. 226 Similarly, there is no inconsistency or incompatibility between the pleaded duty of care owed by the Commonwealth parties to DLZ18 in respect of her time on Nauru and the statutory duty contained in s 198AD(2) of the Migration Act. As already stated, the duty of an officer under that provision to take, as soon as reasonably practicable, an unauthorised maritime arrival to whom the section applies from Australia to a regional processing country says nothing about any common law duty of care owed by the Commonwealth in respect of such a person after they are taken to the regional processing country. 227 Nor is there any inconsistency or incompatibility with the pleaded duty of care owed by the Commonwealth parties to DLZ18 in respect of her time on Nauru and the purpose of Subdiv B. As indicated, that purpose, as reflected in s 198AA and other provisions in that subdivision, has nothing to say about duties of care owed by the Commonwealth to persons who have been taken to a regional processing country in relation to acts or omissions which affect such persons there. The only exception is s 198AHA but, on its proper construction, it provides no support to this aspect of the Commonwealth parties' defence. 228 Accordingly, for these reasons, the bar in s 494AB(1)(ca) does not apply to DLZ18's pleaded case in negligence. 229 In their defence in respect of DLZ18, the Commonwealth parties contended that s 494AB(1)(ca) applies because "the existence of the alleged duty of care, and the alleged liability for damages and other relief claimed, are matters which depend significantly upon the application and effect of provisions" in Subdiv B (emphasis added). 230 In this case, unlike some other cases, DLZ18 is seeking damages only, and she makes no claim for injunctive relief. We have already explained why we consider that s 494AB(1)(ca) does not apply to her claim for damages based on her common law claim in negligence. No further issue arises with respect to s 494AB(1)(ca). Nor does any issue arise in her case with respect to ss 494AB(1)(a) or (d), as will be seen below.

Applicant BXD18's proceeding 231 BXD18's pleaded case is in common law negligence. The relevant paragraphs of the amended statement of claim relating to the pleaded common law duty of care owed by the Commonwealth parties to BXD18 while she was detained on Nauru, and the breach of that duty of care, make no express or implicit reference to any of the statutory provisions in Subdiv B. Even if, as pleaded by the Commonwealth parties in their defence, the relevant parts of the statement of claim were read as alleging a breach of duties of care as a result of actions taken, or omitted to have been taken, under s 198AHA, this is insufficient to attract the bar when regard is had to the proper construction of that provision. 232 Similarly, there is no inconsistency or incompatibility between the pleaded duty of care owed by the Commonwealth parties to BXD18 in respect of her time on Nauru and the statutory duty contained in s 198AD(2) of the Migration Act. As already indicated, the duty of an officer under that provision to take, as soon as reasonably practicable, an unauthorised maritime arrival to whom the section applies from Australia to a regional processing country says nothing about any common law duty of care which is owed by the Commonwealth in respect of such a person after they are taken to the regional processing country. 233 Nor is there any inconsistency or incompatibility with the pleaded duty of care owed by the Commonwealth parties to BXD18 in respect of her time on Nauru and the purpose of Subdiv B. That purpose, as reflected in s 198AA and other provisions in that subdivision, has nothing to say about duties of care owed by the Commonwealth to persons who have been taken to a regional processing country in relation to acts or omissions which affect such persons there. The only exception is s 198AHA but, on its proper construction, it provides no support to this aspect of the Commonwealth parties' defence. 234 Accordingly, for these reasons, the bar in s 494AB(1)(ca) does not apply to BXD18's pleaded case in negligence. 235 In their defence in respect of BXD18, the Commonwealth parties contended that s 494AB(1)(ca) applies because "the exercise of the alleged duty of care, and the alleged liability for damages and other relief claimed, are matters which depend significantly upon the application and effect of provisions" in Subdiv B (emphasis added). 236 We set out at [273] below the terms of BXD18's original application to this Court. It is in her amended originating application and amended statement of claim that BXD18 seeks damages as well as injunctive relief, set out below at [276]. 237 We have explained above why we consider that s 494AB(1)(ca) does not apply to BXD18's claim for damages which is based on her common law claim in negligence. On the basis of the pleadings, the agreed facts and evidence before the Court, we are also not satisfied that BXD18's amended claims for injunctive relief attract the bar in s 494AB(1)(ca). In their defence at [33]-[35], the Commonwealth parties rely on the bar in s 494AB(1)(ca) only in connection with BXD18's pleaded case in negligence. They do not assert that the bar in s 494AB(1)(ca) was attracted because the injunctive relief that BXD18 claimed would, if granted, prevent her removal under s 198AD(2) in Subdiv B, to which s 494AB(1)(ca) relates. We note that the reference in [34(b)] of the defence in BXD18's case to s 198AD is a reference to BXD18 having been removed from Australia to Nauru originally, not to her future removal from Australia. 238 Further, the duty to remove a transitory person from Australia under s 198AD(2) only arises if the conditions in s 198AH(1A) are met, including that BXD18 "no longer needs to be in Australia for the temporary purpose (whether or not the purpose has been achieved)". The agreed statement of facts in BXD18's case does not identify the relevant "temporary purpose", other than to say in [13] that she was transferred to Australia "for medical treatment". Nothing in the agreed facts or uncontested evidence describes the nature of the relevant medical treatment or its anticipated duration. The Commonwealth parties have not argued that the duty under s 198AD(2) has yet arisen. In these circumstances, we would not find that the bar in s 494AB(1)(ca) is attracted because the injunctive relief sought by BXD18 trespasses into the field covered by s 198AD(2). 239 This is not to say that the bar in s 494AB(1)(ca) cannot be attracted at a later date when the grant of her claim for injunctive relief falls for consideration, by reason of the circumstances that may then be said to give rise to the duty under s 198AD(2) to remove BXD18 from Australia to a regional processing country. Deciding whether or not to grant injunctive relief in this circumstance would require adjudication on whether the duty in s 198AD(2) is operative at the time. Such a proceeding would require determination of rights and obligations sourced in a relevant part of the Migration Act; and BXD18's case would then resemble SGS v Minister for Immigration and Border Protection [2015] NTSC 62; 34 NTLR 224. There, proceedings were commenced in the Supreme Court of the Northern Territory on behalf of a child who was a transitory person. She sought damages for injuries suffered while she was detained on Nauru, as well as an injunction restraining the Minister from returning her to Nauru. The plaintiff and her parents had been brought to Darwin for the purpose of her father receiving medical treatment. 240 In determining preliminary separate questions relating to the Court's jurisdiction to entertain the proceedings, Hiley J acted upon a concession from the Commonwealth defendants that the plaintiff's claim in tort was actionable and within that Court's jurisdiction. It may be that, because of this concession, his Honour made no reference to s 198AHA notwithstanding that this provision was in force for several months before SGS was argued and determined. Although his Honour held at [70] that ss 494AB(1)(c), (ca) and (d) of the Migration Act did not apply to that part of the plaintiff's proceedings which related to tortious conduct said to have occurred on Nauru, he also held at [71] that the injunctive relief sought by the plaintiff fell within both ss 494AB(1)(ca) and (d). His Honour explained at [71] and [72]: However, in so far as these proceedings seek injunctive relief of the kind sought by the plaintiff, I do consider that they fall within s 494AB(1) (ca) and (d). Once the plaintiff no longer needs to be in Australia for the temporary purpose of her father's medical treatment s 198AD will apply, by force of s 198AH(1A), unless the minister makes a determination under s 198AE that s 198AD does not apply to her. Section 198AD(2) will then require an officer to take her to a regional processing country, thereby removing her from Australia. The power of the minister to make a determination under s 198AE and the duty of an officer under s 198AD(2) are powers and duties under Subdiv B of Div 8 of Pt 2. The granting of the injunction sought would prevent such an officer from performing his or her statutory obligation to remove the plaintiff from Australia. Thus, while it was held that the Supreme Court of the Northern Territory did not have jurisdiction to grant the injunctive relief sought by the plaintiff, it did have jurisdiction to entertain her claim for damages. In effect, the claim for injunctive relief was excised. 241 It is convenient to note at this point that, while we do not consider that the proceedings in BXD18's case attracts the bar in s 494AB(1)(ca) (or s 494AB(1)(a): see below), we do consider that these proceedings attract the bar in s 494AB(1)(d). As indicated at the end of these reasons, we have not been invited to consider the possible effect of any application to amend.

Applicant DIZ18's proceeding 242 DIZ18's pleaded case is in common law negligence. The relevant paragraphs of the amended statement of claim relating to the pleaded common law duty of care owed by the Commonwealth parties to DIZ18 while she was detained on Nauru, and the breach of that duty of care, make no express or implicit reference to any of the statutory provisions in Subdiv B. Even if, as pleaded by the Commonwealth parties in their defence, the relevant parts of the statement of claim were read as alleging a breach of duties of care as a result of actions taken, or omitted to have been taken, under s 198AHA, this is insufficient to attract the bar when regard is had to the proper construction of that provision. 243 Similarly, there is no inconsistency or incompatibility between the pleaded duty of care owed by the Commonwealth parties to her in respect of her time on Nauru and the statutory duty contained in s 198AD(2) of the Migration Act. The duty of an officer under that provision to take, as soon as reasonably practicable, an unauthorised maritime arrival to whom the section applies from Australia to a regional processing country says nothing about any common law duty of care which is owed by the Commonwealth in respect of such a person after they are taken to the regional processing country. 244 Nor is there any inconsistency or incompatibility with the pleaded duty of care owed by the Commonwealth parties to DIZ18 in respect of her time on Nauru and the purpose of Subdiv B. That purpose, as reflected in s 198AA and other provisions in that subdivision, has nothing to say about duties of care owed by the Commonwealth to persons who have been taken to a regional processing country in relation to acts or omissions which affect such persons there. The only exception is s 198AHA but, on its proper construction, it provides no support to this aspect of the Commonwealth parties' defence. 245 Accordingly, for these reasons, the bar in s 494AB(1)(ca) does not apply to DIZ18's pleaded case in negligence. 246 In their defence in respect of DIZ18, the Commonwealth parties contended that s 494AB(1)(ca) applies because "the existence of the alleged duty of care, and the alleged liability for damages and other relief claimed, are matters which depend significantly upon the application and effect of provisions" in Subdiv B (emphasis added). 247 In her original statement of claim DIZ18 sought an injunction prohibiting the Commonwealth parties from taking steps to transfer DIZ18 from PNG back to Nauru. This could not attract the bar in s 494AB(1)(ca) because the duty in s 198AD(2) in Subdiv B, to which s 494AB(1)(ca) relates, could not arise as she was not seeking to prevent her removal from Australia. Since her arrival in Australia on 4 July 2018, her pleadings have been relevantly amended. Besides damages, DIZ18 now seeks an injunction requiring the Commonwealth parties to continue to take all steps within their power to ensure that she receives treatment, including long-term care and follow-up, in a location with access to quality, multi-disciplinary specialist paediatric care. At [34] of her amended statement of claim, DIZ18 alleges that by reason of her injuries, she requires and will require long-term rehabilitation, specialist review and follow-up with her treating practitioners in Australia, this standard of care not being available in Nauru. 248 We have explained above why we consider that s 494AB(1)(ca) does not apply to DIZ18's claim for damages based on her common law claim in negligence. On the basis of the pleadings, the agreed facts and evidence before the Court, we are also not satisfied that DIZ18's current claim for injunctive relief attracts the bar in s 494AB(1)(ca). This claim does not in terms seek to prevent DIZ18's removal from Australia; when read with [34] of DIZ18's amended statement of claim, however, it is clear that it is directed to this end, at least while DIZ18 is undergoing rehabilitation, specialist review and follow-up. 249 In their defence at [40]-[42], however, the Commonwealth parties rely on the bar in s 494AB(1)(ca) only in connection with DIZ18's pleaded case in negligence. They do not assert that the bar in s 494AB(1)(ca) was attracted because the injunctive relief that DIZ18 claimed would, if granted, prevent her removal under s 198AD(2) in Subdiv B, to which s 494AB(1)(ca) relates. We note that the reference in [41.2] of the defence in DIZ18's case to s 198AD is a reference to DIZ18's parents having been removed from Australia to Nauru originally, not to her and her parents' future removal from Australia. 250 Further, it will be recalled that the duty to remove a transitory person from Australia under s 198AD(2) only arises if the conditions in s 198AH(1A) are met, including that DIZ18 "no longer needs to be in Australia for the temporary purpose (whether or not the purpose has been achieved)". Neither the agreed statement of facts nor the uncontested evidence indicates the nature of "the temporary purpose" in DIZ18's case. Paragraph [42] of the statement of agreed facts in her case states merely that she was brought to Australia from PNG. There is no express statement of the purpose of her removal from PNG to Australia. The Commonwealth parties have not argued that a duty under s 198AD(2) has arisen. In these circumstances, we would not find that the bar in s 494AB(1)(ca) is attracted because the injunctive relief sought by her trespasses into the field covered by s 198AD(2). 251 This is not to say that the bar in s 494AB(1)(ca) cannot be attracted at a later date when the grant of DIZ18's claim for injunctive relief falls for consideration, by reason of the circumstances that may then be said to give rise to a duty under s 198AD(2) to remove her from Australia to a regional processing country. Deciding whether or not to grant injunctive relief in this circumstance would require adjudication of whether the duty in s 198AD(2) is operative at the time. This would require an identification of the relevant "temporary purpose" in order to assess whether DIZ18 did or did not need to remain in Australia for that temporary purpose (s 198AH(1A)). Such a proceeding would require determination of rights and obligations sourced in a relevant part of the Migration Act. As in BXD18's case, the proceedings in DIZ18's case would then raise issues akin to those that fell for determination in SGS, where Hiley J held that the injunctive relief sought by the plaintiff fell within both ss 494AB(1)(ca) and (d). 252 It is convenient to note at this point that, while we do not consider that the proceedings in DIZ18's case attracts the bar in s 494AB(1)(ca), we do consider that her proceedings attract the bars in ss 494AB(1)(a) and (d). As indicated at the end of these reasons, we have not been invited to consider the possible effect of any application to amend.

DOES THE BAR IN SECTION 494AB(1)(A) AND/OR (D) APPLY TO ANY OF THE PROCEEDINGS? 253 It is next necessary to consider each of the four proceedings to answer, in each case, whether or not they are "proceedings relating to the exercise of powers under section 198B" within the meaning of s 494AB(1)(a) or "proceedings relating to the removal of a transitory person from Australia under this Act" within the meaning of s 494AB(1)(d). In seeking to establish that each of the proceedings has the character required by either of these provisions, the Commonwealth parties focussed primarily on the interlocutory and final relief sought (and in some cases obtained) by each applicant. In some cases, the Commonwealth parties also relied on the terms of the duty pleaded. 254 First it is desirable to say something specifically about the legislative history of s 198B. That section was added by the Transitional Movement Act, which was the same Act that introduced s 494AB. The Revised Explanatory Memorandum to the Migration Legislation Amendment (Transitional Movement) Bill 2002 (2002 Explanatory Memorandum) stated that the amendments allow a "transitory person" to be brought to Australia without a visa for a temporary purpose. That Explanatory Memorandum also stated that the new section introduced a power to bring a "transitory person" to Australia from a country or place outside Australia for "temporary purposes". It was stated that it also provided statutory authority for the exercise of the powers necessary to effect the transitional movement of such persons. 255 We infer that none of the four applicants was granted a visa for the purpose of being brought to Australia for medical treatment. In relation to the Sydney cohort there is evidence in this respect, which we accept, in the affidavits filed on behalf of the Commonwealth parties, being the affidavits of Louise Buchanan. For the Melbourne cohort, as discussed below, we would uphold the hearsay objection to the admissibility of parts of the affidavits of Dejan Lukic. As indicated below, however, this has no practical outcome, since we infer from the circumstances that no such visas were granted. This is not to say that such a visa could not have been granted to any applicant, but it does lead us to infer that the power in fact exercised in each case was the power conferred by s 198B. By s 42(2A)(ca) of the Migration Act the prohibition on a non-citizen travelling to Australia without a valid visa does not apply to a non-citizen in relation to travel to Australia if, relevantly, the non-citizen is brought to Australia under s 198B.

Applicant FRM17's proceeding 256 In FRM17's case, as we have said, the originating application was dated 20 December 2017. FRM17 was then on Nauru. FRM17 claimed an interim injunction restraining the Commonwealth parties from, relevantly, detaining FRM17 on Nauru or at any other offshore processing centre not within Australia and from not permitting FRM17 to travel to another country for the purpose of obtaining urgent psychiatric medical attention. Final relief was claimed to the effect that the psychiatric care of FRM17 not be provided on Nauru or in any other offshore environment. It was claimed that the care be consistent with the expert psychiatric medical reports of Professor Louise Newman dated 19 December 2017 and Dr Nick Martin dated 19 December 2017. The form of relief sought in FRM17's statement of claim dated 11 January 2018 referred to reports of Professor Newman dated 19, 21 and 22 December 2017, although this difference is not presently material. The Court was told that the claim for a permanent injunction is no longer pressed, but that of course could only go to the question of continuation rather than institution of the proceedings. 257 Professor Newman reported on 19 December 2017 that FRM17 was in need of immediate comprehensive psychiatric assessment by a qualified specialist in child psychiatry and required treatment in an inpatient child mental health facility with appropriate supervision. She recommended that the urgent transfer to a child psychiatric facility be arranged. On 21 December 2017 Professor Newman indicated, following correspondence between the parties' representatives that was brought to her attention, that she remained of the view that FRM17's condition was extremely serious and not one that could be safely managed in a community setting on Nauru. She repeated and expanded upon this view in her 22 December 2017 report. 258 Mr Watson SC accepted that FRM17 was brought to Australia following a contested hearing and a court order. It may also be accepted that the legal representatives of FRM17 in this proceeding sought an order that she be taken from Nauru for the particular medical treatment. The orders sought in the originating application do not in terms require FRM17 to be brought to Australia; nor do the orders made by a judge of this Court on 22 December 2017. 259 On 24 December 2017, FRM17 arrived in Australia and she remains here. 260 As to s 494AB(1)(a), the Commonwealth parties plead that the proceedings related to the exercise of powers under s 198B because FRM17 sought interlocutory relief which, in effect, required her transfer to Australia for a medical purpose and the Migration Act contemplated that such a transfer would be effected through the exercise of power under s 198B and, in fact, the order requiring FRM17's transfer was complied with through an exercise of power under s 198B. The Commonwealth parties also plead that FRM17 alleged, in effect, that she should have been removed from Nauru, which in law and in fact would have been achieved if required through the exercise of power under s 198B. 261 In our opinion, these circumstances do not mean that these proceedings are proceedings relating to the exercise of powers under s 198B. FRM17 did not in terms invoke that power or seek that it be exercised and did not obtain an order requiring the Commonwealth parties to exercise that power. The interim orders obtained did not require that the applicant be brought to Australia, merely that FRM17 be placed in a specialist child mental health facility meeting particular conditions. That order could have been satisfied by FRM17 being taken or being permitted to travel to any country where such facilities were available. The exercise of that power was therefore not essential to compliance with the court order referred to at [258] above. Further, FRM17 did not challenge any exercise of the power conferred by s 198B or plead a case in negligence arising from a statutory duty conditioning the exercise of that power. 262 We reject the Commonwealth parties' submission that, as a matter of construction, s 494AB(1) is not restricted to a case where the orders sought can only be complied with by exercising a relevant power, and instead all that is required is that the power provides one of a number of means of so complying. This submission was not developed in detail but appears to rest principally on the proposition that "relating to" is a broad expression. As we have explained, the breadth of the phrase "relating to" may be accepted but that does not of itself answer the question of statutory construction. The Commonwealth parties' submission may also reflect an aspect of their argument about inconsistency or incoherence reasoning, which we have rejected at [213] above. 263 As to s 494AB(1)(d), the Commonwealth parties plead that the relief which FRM17 seeks, in effect, prevents her removal from Australia. It is pleaded that FRM17 is presently in Australia and the effect of the orders sought requiring her to receive medical care in accordance with particular recommendations will be to prevent her being removed from Australia. 264 In our opinion, these circumstances do not mean that these proceedings are proceedings relating to the removal of FRM17 from Australia. Indeed, no issue of removal has arisen. It is clear that FRM17's case is distinguishable from SGS, which we have discussed earlier. FRM17's proceedings do not, for example, challenge any determination under s 198AH(1A)(c) that she no longer needs to be in Australia for a temporary purpose within the meaning of s 198B. As we have already noted, the claim for a permanent injunction is no longer pressed.

Applicant DLZ18's proceeding 265 In DLZ18's case, as we have said, proceedings were commenced on 4 July 2018. 266 The interlocutory application dated 4 July 2018 claimed, relevantly, an order for the Minister for Home Affairs to immediately transfer DLZ18: … to a location where the Respondent can obtain for the Applicant urgent paediatric physical and psychiatric care that is clinically recommended, where that care is not provided to the Applicant in Nauru or in any other off-shore environment and where the care is consistent with the expert psychiatric medical reports of Dr Patricia Schmid, Dr Joshua Francis and OSSTT Counsellors Sue Mitchell and Fleur Noonan, and the advice provided by Professor Louise Newman as detailed in the affidavit of Anna Talbot dated 4 July 2018. 267 These reports were to the effect that DLZ18 immediately required intensive care in an inpatient child and adolescent psychiatric facility under the care of child and adolescent clinicians including child psychiatrists and psychologists. Psychiatric inpatient facilities were not available in Nauru. Professor Newman was of the opinion that DLZ18 needed urgent treatment, it was not possible to treat her in Nauru and: "She needs a paediatrician, and she should go to a children's hospital such as Westmead. She should see the paediatrician first, and then mental health." 268 DLZ18 was brought to Australia on 6 July 2018. As we have said, on the same day a judge of the Court dismissed the interlocutory application filed two days earlier. 269 As noted above, an originating application and statement of claim were filed in DLZ18's case on 22 and 28 November 2018 respectively. Paragraphs 77, 78 and 79 of the statement of claim were in the following terms: [77] From about June 2018 - ie when the respondents became aware, or should have become aware, that the first applicant's Psychological Condition had worsened to such a degree that appropriate facilities and medical care were not available on Nauru - the respondent (sic) came under an additional duty to take reasonable care: 77.1 To remove the applicant from Nauru to a place with appropriate medical facilities and where appropriate medical treatment could be administered for their (sic) Psychological Condition. [78] From about August 2018 - i.e. when the respondents became aware, or should have become aware that the first applicant required parental support from her father for effective medical treatment that could only be obtained by the respondents - the respondent (sic) came under an additional duty to take reasonable care: 78.1 To take steps to ensure the first applicant had access to parental support from her father. … [79] In breach of the duty of care they owed to the applicants, the respondents failed: 79.1 To protect the applicants from unreasonable risks of harm, including psychological harm, following the removal from Christmas Island and their relocation to Nauru; 79.2 To take measures, including the provision of appropriate medical treatment and reunification of the first and second applicants with their father/husband by the first applicant's treating doctors at Westmead Hospital, in the event the first and second applicants manifested adverse effects. The final relief claimed in [83] of the statement of claim was orders for damages, costs and such further order as the Court deems appropriate. 270 In the defence that was filed by the Commonwealth parties (which, as we have noted, erroneously referred to s 494AB(1)(b)), it was pleaded that the proceeding related to the exercise of power under s 198B because the allegations in [77]-[79] of the statement of claim included within them an allegation that the Commonwealth parties ought to have transferred DLZ18, FZR18 and DLZ18's father from Nauru to Australia. It was pleaded that as to such transfer, the Migration Act contemplated that it will be effected through the exercise of power under s 198B and any such transfer will in fact be effected through an exercise of power under s 198B, thus attracting the bar in s 494AB(1)(a). 271 As with FRM17, in our opinion, these circumstances did not mean that the current proceedings are proceedings relating to the exercise of powers under s 198B. DLZ18 did not in terms invoke that power or seek that it be exercised and did not obtain an order requiring the Commonwealth parties to exercise that power. No interlocutory orders were made. Further, DLZ18 did not challenge any exercise of the power in s 198B or plead a case in negligence arising from a statutory duty conditioning the exercise of that power. We therefore conclude that the current proceedings were not barred by s 494AB(1)(a). 272 The Commonwealth parties' pleading did not allege that these proceedings were proceedings relating to the removal of a transitory person from Australia within s 494AB(1)(d). It is therefore unnecessary for us to consider that provision in relation to this proceeding.

Applicant BXD18's proceeding 273 In relation to BXD18's case, as we have said BXD18 commenced proceedings in this Court in April 2018. The originating application claimed an injunction requiring the Commonwealth to take all steps within its power to ensure that BXD18 received treatment in a specialist child mental health treatment facility with comprehensive tertiary level child psychiatric assessment, with her family, in accordance with the primary recommendations of Dr Vernon Reynolds, an IHMS psychiatrist, made on 5 April 2018. Those recommendations of Dr Reynolds were "to immediately transfer [BXD18] and family to an appropriate Child and Adolescent Inpatient unit that has the skills and resources to support her and her family in their recovery. We are unable to effectively manage this situation and in particular to manage the serious and imminent risk concerns. Any delay in this process of transfer increases the potential for further harm and suicidal behaviour." The originating application also claimed a declaration that the Commonwealth parties will contravene their alleged duty of care if they fail to take reasonable steps to ensure BXD18 is taken to a place other than Nauru where she can receive that treatment. The same relief was claimed in BXD18's statement of claim filed on 16 April 2018. 274 The interlocutory application dated 13 April 2018 relevantly sought the following: 3. An order that the Minister by himself or by his Department, officers, agents or delegates shall immediately transfer the Applicant, together with her father BXG18 as the Applicant's guardian, and her brother … as a dependant minor of the Applicant's guardian, to a location where the Applicant can receive the Specified Treatment. For the purpose of this application, 'Specified Treatment' means: a. immediate comprehensive psychiatric assessment by a qualified specialist in child psychiatry; b. treatment in an inpatient child mental health facility with appropriate supervision; and c. an evaluation to clarify the Applicant's diagnosis. d. together with any associated or additional treatment which made be identified as necessary. 275 No such interlocutory order was made. On 14 April 2018, having already made a decision for BXD18 to be brought to Australia the Commonwealth parties made arrangements for BXD18, her father and brother to be transferred to Australia on a flight on 15 April 2018. 276 By an amended originating application filed on 27 August 2018, BXD18 instead sought: injunctions requiring the Commonwealth parties to resettle her and her family in a country which is a signatory to the Refugees Convention and not to take any steps to remove her and her family from Australia until then; alternatively, requiring the Commonwealth parties not to take steps to remove her and her family to any regional processing country where she would be at risk of suffering various forms of harm; alternatively, requiring the Commonwealth parties not to take steps to remove BXD18 and her family from Australia (other than to a Refugees Convention signatory country which has accepted them for resettlement) until BXD18 had reached maximum medical improvement, provided that her psychiatric condition would not be at risk of deterioration again. As indicated at [142] above, BXD18's amended statement of claim claimed the same relief. 277 The following paragraphs of the amended statement of claim are relevant to the issue of the applicability of s 494AB(1)(a). By [14], under the heading standard of care, it was pleaded that once BXD18 became at risk of suffering physical, emotional and/or child abuse and/or psychiatric injury on Nauru reasonable care to prevent such abuse or injury required the Commonwealth parties to remove BXD18 from Nauru. Under the heading breach of duty, it was pleaded in [17] that it was reasonably foreseeable that not removing BXD18 from Nauru would lead to her suffering physical, emotional and/or child abuse and/or suffering psychiatric injury. By [22] it was pleaded that as a result of the Commonwealth parties' failure to remove BXD18 from Nauru she had suffered injury, loss and damage. By [23] it was pleaded that had the Commonwealth parties removed BXD18 from Nauru she would not have suffered injury as aforesaid. 278 By their defence to the amended statement of claim, the Commonwealth parties allege that the proceeding was one relating to the exercise of power under s 198B, and thus barred by s 494AB(1)(a), because BXD18 sought interlocutory relief which effectively required a transfer to Australia for a medical purpose; as to such a transfer, the Migration Act contemplated that it would be effected through the exercise of power under s 198B and BXD18's transfer was in fact effected through an exercise of power under that section; and BXD18 alleges that she should have been removed from Nauru, which in law and in fact would be achieved if required through the exercise of power under s 198B. In this respect the Commonwealth parties referred to the paragraphs of the amended statement of claim we have summarised above. 279 As considered above, in our opinion, these circumstances did not mean that these proceedings are proceedings relating to the exercise of powers under s 198B. BXD18 did not in terms invoke that power or seek that it be exercised and did not obtain an order requiring the Commonwealth parties to exercise that power. No relevant interlocutory orders were made: the Commonwealth parties decided to transfer BXD18 and members of the family to Australia. Further, BXD18 did not challenge any exercise of the power in s 198B or plead a case in negligence arising from a statutory duty conditioning the exercise of that power. We therefore conclude that these proceedings were not barred by s 494AB(1)(a). 280 By their defence the Commonwealth parties also allege, with reference to s 494AB(1)(d), that BXD18 seeks relief preventing her removal from Australia. 281 When BXD18's proceedings were commenced, in our opinion they were not proceedings to which s 494AB(1)(d) could be said to apply as it said nothing about the removal of BXD18 from Australia. However, the terms in which the matter is pleaded in BXD18's amended statement of claim and amended originating application, as to which see [142] and [276] above, mean that these proceedings are proceedings relating to the removal of BXD18 from Australia under the Migration Act. Although no issue of actual or threatened removal has arisen, injunctive relief is expressly sought against BXD18's removal. As did French J in Applicants WAIV v Minister for Immigration and Multicultural and Indigenous Affairs [2002] FCA 1186 at [7] and [31], we would conclude that as pleaded this proceeding relates to the removal from Australia of BXD18, being a transitory person. We also note that Hiley J reached the same conclusion in SGS at [71] with reference to the relief sought in the statement of claim as set out at [6]. We conclude that BXD18's proceedings, as presently pleaded, attract the bar in s 494AB(1)(d).

Applicant DIZ18's proceeding 282 DIZ18 was born on Nauru. As we have said, on or around 14 June 2018 the Commonwealth parties arranged to transfer her and her mother to Port Moresby for DIZ18 to receive medical treatment. On or about 27 June 2018, the Commonwealth parties determined that DIZ18 and her mother would be taken back to Nauru from Port Moresby. 283 By her originating application filed on 29 June 2018, DIZ18 relevantly sought the following relief: 1. An injunction requiring the Commonwealth and the Minister to take all steps within their power to ensure that, upon medical discharge from the hospital in Papua New Guinea where the Applicant is presently being treated, the Applicant is transferred to a location in Australia where the Applicant receives an MRI head scan and specialist paediatric treatment, care and follow up in accordance with the recommendations of Dr Michael Harbord dated 27 June 2018. 2. Alternatively to 1, the Commonwealth and the Minister cease to fail to discharge their duty to procure and ensure the continued provision to the Applicant of the care required in accordance with the recommendations of Dr Michael Harbord 3. A declaration that the Respondents will contravene their duty of care to the Applicant, to exercise reasonable care to discharge the responsibility that they have assumed for her health and welfare, if they fail to take reasonable steps to ensure the continued provision to the Applicant of the care required in accordance with the recommendations of [expert report]. 284 The recommendations of Dr Harbord in his 27 June 2018 report, being signed notes of the telephone conference with him on that date, were: "this child requires that her clinical state is monitored by a specialist paediatrician in order to monitor and observe any regression in her condition. The diagnosis and treatment of this condition must be overseen by a paediatric neurologist. Its treatment and presentation would not be familiar to a paediatrician." Dr Harbord continued: This child could not obtain the treatment that would meet the standard of care while on Nauru for a number of reasons. Firstly, this patient requires ongoing and regular paediatric review. In Australia, such a patient would initially be seen fortnightly by a paediatrician, progressing to monthly, 2 monthly and finally a 3 to 6 monthly basis. She would be closely monitored by a paediatrician for a 2 to 3 year period and closely monitored again as she reaches school age. A paediatric neurologist would be involved in her care should any neurological issues develop. It would not meet standard of care for this patient to be monitored by a resident medical officer alone. Secondly, continuity of care for this patient is particularly important. Monitoring of her cognitive condition involves looking for slight and subtle issues of regression relative to her own development. This could not be achieved to a satisfactory standard without regular review by the same paediatrician. 285 By her interlocutory application dated 29 June 2018 DIZ18 sought: 1. An order that the Minister, by himself or by his Department, officers, agents or delegates shall, immediately upon the Applicant being medically discharged from the hospital in Papua New Guinea where she is presently being treaded (sic), transfer the Applicant, together with her mother (DJB18), to a location in Australia where the Applicant can receive the Specified Treatment. For the purpose of this application, 'Specified Treatment' means: a. MRI head scan as soon as possible; b. Assessment, long term care and follow up by a pediatric neurologist and multi disciplinary specialist pediatric team. 2. An order that the Minister, by himself or by his Department, officers, agents or delegates shall, as soon as reasonably practicable after the Applicant has been medically discharged from the hospital in Papua New Guinea where she is presently being treaded (sic), transfer the Applicant's father (DJA18), from Nauru to the same location in Australia where the Applicant is being taken, so that the Applicant can be reunited with him. 286 As already stated, in her original statement of claim DIZ18 sought an injunction prohibiting the Commonwealth parties from taking steps to transfer her back to Nauru; and at [34] of her amended statement of claim she alleged that by reason of her injuries, she requires and will require long-term rehabilitation, specialist review and follow-up with her treating practitioners in Australia. As already noted, she sought an injunction requiring the Commonwealth parties to take and to continue to take all steps within their power to ensure that she receives treatment, including long-term care and follow-up, in a location with access to quality, multi-disciplinary specialist paediatric care. 287 Orders were made on 3 July 2018 by a judge of this Court. Those orders first noted the undertaking given by the Commonwealth parties not to take steps to return DIZ18 to Nauru pending the outcome of the proceedings, unless otherwise agreed between the parties. The following order was also made on that date: 1. As soon as reasonably practicable and: (a) within 48 hours the Respondents ensure that the Applicant with her mother are brought to Australia from Papua New Guinea; (b) by 6 July 2018 the Respondents ensure that the Applicant's father is brought to Australia from Nauru to join his family; to ensure that the Applicant receives treatment at an Australian tertiary level hospital in accordance with the recommendations of Michael Harbord dated 28 June and 1 July 2018 including, as soon as practicable: (i) an MRI brain scan with sedation performed by a paediatric anaesthetist; (ii) EEG testing; and (iii) review and any treatment overseen by a paediatric neurologist. 288 By their defence dated 19 March 2019 to DIZ18's amended statement of claim the Commonwealth parties contended that the proceedings in this Court were barred by s 494AB(1)(a) because they related to the exercise of power under s 198B. This was said to be because DIZ18 sought relief which required her transfer to Australia for a medical purpose; as to such a transfer the Migration Act contemplated that it will be effected through the exercise of power under s 198B of the Migration Act and DIZ18's transfer was in fact effected through an exercise of power under that section. 289 These circumstances indicate that, in contrast with the position in BXD18 (see [279] above), these proceedings are proceedings relating to the exercise of powers under s 198B attracting the bar in s 494AB(1)(a). Unlike the position with BXD18, DIZ18 expressly sought in her interlocutory application an order requiring the Commonwealth parties to transfer DIZ18 and her mother to a location in Australia for the purpose of her obtaining medical treatment and an order was made to that effect. It may be accepted that DIZ18 did not in terms invoke that power and that she did not obtain an order expressly requiring the Commonwealth parties to exercise it. Further, the power in s 198B is not the only power pursuant to which the Commonwealth parties might bring a transitory person to Australia from a place outside Australia, at least where the transitory person consents to the transfer for a temporary purpose. Indeed, the Commonwealth parties did not contend that s 198B was the sole power available to bring DIZ18 to Australia. Nonetheless, we accept that the statutory scheme contemplates that usually the power conferred by s 198B was the power to be exercised in the case of temporary transfers to Australia for medical purposes. 290 It may be recalled that, at the relevant date, s 198B provided that a transitory person may be brought to Australia "for a temporary purpose". The 2002 Explanatory Memorandum explained that the temporary purposes for which the power in s 198B may be exercised included allowing a transitory person "to receive medical treatment". Further, as noted above, we would infer that the power conferred by s 198B was the power in fact used to bring DIZ18 to Australia for her treatment since she was not granted a visa prior to or upon her arrival in Australia and she does not presently hold a visa. In these circumstances, the proceedings related to the exercise of powers under s 198B and fell within the bar in s 494AB(1)(a). 291 The Commonwealth parties also contended that DIZ18 sought relief preventing her removal from Australia and the proceedings were therefore barred by s 494AB(1)(d). We accept this submission. Having regard to the combination of [34] in her amended statement of claim and her claim for injunctive relief (in paragraph A of the prayer for relief), we would characterise DIZ18's proceedings, as presently pleaded, as proceedings relating to the removal of a transitory person from Australia under the Migration Act. 292 Although no issue of removal has yet arisen and the proceedings do not, for example, challenge any determination under s 198AH(1A)(c) we would see this case as within the principles in Applicants WAIV at [7] and [31] and in SGS at [71]. For the reasons we have outlined above, the proceedings could not be instituted in this Court and, as presently pleaded, cannot be continued here. As indicated at the end of these reasons, we have not been invited to consider the possible effect of any application to amend.

EVIDENCE AND RULINGS ON EVIDENCE 293 In relation to all four proceedings, the Commonwealth parties submitted that affidavits that were read at the hearings showed that the actual relief being sought in each case was transfer to Australia, being the only place to which the individual applicants could be taken in sufficient time to address their medical needs. 294 While not ruling out the possibility that affidavit material could assist in establishing the character of proceedings, especially where proceedings are not commenced by statement of claim, we do not see that the evidence in any of the four cases takes the matter further than the pleadings. In FRM17's case, the affidavits coincided with the pleadings that care could not be provided in an offshore environment. In DLZ18's and in BXD18's cases, the evidence went no further than the pleadings to which we have referred above. In DIZ18's case, again we do not see that the affidavit evidence takes the matter further than the pleading, which was that DIZ18 be transferred to Australia. 295 DLZ18 relied on the affidavit of her solicitor, Emma Hearne, affirmed on 18 April 2019 and filed in DLZ18's proceeding. FRM17 relied on a different affidavit, although also affirmed by Emma Hearne on 18 April 2019, filed in FRM17's proceeding. 296 BXD18 relied on the affidavit of her lawyer, Jennifer Kanis, affirmed on 24 April 2019 and filed in BXD18's proceeding. DIZ18 relied on a different affidavit, although also affirmed by Jennifer Kanis on 24 April 2019, filed in DIZ18's proceeding. 297 As regards the Sydney cohort, the Commonwealth parties relied on two affidavits of Louise Buchanan, an AGS lawyer: one affidavit affirmed on 18 April 2019 was filed in DLZ18's proceeding and the other affirmed on 23 April 2019 was filed in FRM17's proceeding. As regards the Melbourne cohort, the Commonwealth parties relied on two affidavits of Dejan Lukic, an AGS lawyer: one affidavit affirmed on 18 April 2019 was filed in BXD18's proceeding and the other was affirmed on 23 April 2019 and filed in DIZ18's proceeding. Mr Lukic's affidavits were admitted subject to objections. It was said by Mr Horan QC that the whole of the two affidavits was irrelevant. We overrule that objection, being of the opinion that this material is sufficiently relevant: see s 55 of the Evidence Act 1995 (Cth). 298 It was also said that [10.1]-[10.3] of the affidavit of Mr Lukic filed in BXD18's proceeding were inadmissible expressions of opinion or hearsay, that annexure DL-8 contained inadmissible expressions of opinion, and that annexures DL-8 and DL-9 did not satisfy the business records exception to the hearsay rule and were inadmissible as hearsay. Similar objections were taken to [5.1]-[5.3] of Mr Lukic's affidavit filed in DIZ18's proceeding and to annexures DL-3 and DL-4. 299 It may be recalled that objection was taken by Mr Horan QC on the basis that the challenged parts of his affidavits were inadmissible as hearsay unless "fixed up". It is evident that, in order to "fix up" these hearsay objections, the Commonwealth parties subsequently filed two affidavits of Alyce Kathryn Johnson affirmed on 7 May 2019, one in BXD18's proceeding and the other in DIZ18's proceeding. Unfortunately for the Commonwealth parties, it appears that those affidavits were not read or tendered and the parties did not inform us that it was agreed that we should take the affidavits into account. In these circumstances, we would uphold the objections in so far as they were based on hearsay grounds. As indicated, this is immaterial because we would infer that neither of those applicants had visas to enter Australia.

CONCLUSION AND ORDERS 300 The questions that were ordered to be separately answered in each of these four cases were as follows: (a) when the proceeding was commenced in the Federal Court, was the effect of s 494AB of the Migration Act that it could not be instituted? and (b) is the effect of s 494AB of the Migration Act that the proceeding cannot be continued in the Federal Court? 301 For the reasons we have stated, we answer these questions in each of FRM17's case and DLZ18's case: (a) No. (b) No. 302 In the case of BXD18, we answer the questions: (a) No. (b) Yes. Our answers take this form because the proceedings as instituted were not, in our opinion, proceedings within ss 494AB(1)(a), (ca) or (d). As amended, however, they fall within s 494AB(1)(d). 303 In the case of DIZ18, we answer the questions: (a) Yes. (b) Yes. Our answers take this form because the proceedings as instituted were proceedings within s 494AB(1)(a) and, as continued, proceedings within s 494AB(1)(d). 304 We say nothing about what the position may be if DIZ18 or BXD18 were to apply to amend their pleadings and whether, in those circumstances, the consequence is that, retrospectively, the proceedings could be instituted or continued in this Court: see, for example, Gloucester Shire Council v Fitch Ratings, Inc (No 2) [2017] FCA 248 at [235]-[238]. Those matters were not argued and, in our opinion, were not within the contemplation of the two separate questions. 305 The Commonwealth parties are to pay the applicants' costs, as agreed or assessed. We record our opinion that these four cases were test cases, so that although the Commonwealth parties have been successful in two of the cases, we also order that they pay the applicants' costs, as agreed or assessed, in those cases as well. I certify that the preceding three hundred and five (305) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justices Kenny, Robertson and Griffiths.