On 6 and 7 May 1996 there was a riot by prisoners of the Yatala Labour Prison, resulting in a number of Correctional Services Officers being taken hostage by a number of prisoners, quite serious and lasting physical and mental injury to a number of Correctional Service Officers and substantial damage to property. The applicant was one of the core group allegedly responsible for the incident. Along with others he was subsequently charged with four counts of unlawful imprisonment, one count of damage to property and four counts of assault occasioning actual bodily harm. Other members of the group were also charged with other offences. All members of the group are awaiting trial on those charges.

On 10 May 1996 the then General Manager of Yatala Labour Prison directed pursuant to s36(2)(d) of the Correctional Services Act 1982 ("the Act") that the applicant be kept separate and apart from all other prisoners until the direction was revoked. The order was said to have been made in the interests of security or good order within the correctional institution.

On 11 February 1997 the then General Manager of Yatala Labour Prison made an order revoking the previous order and then made a further order in similar terms pursuant to the same paragraph of s36(2). On 12 February 1997 the Chief Executive Officer of the Department for Correctional Services revoked the Separation Order and then immediately made another order also based on the same grounds. The substance of the order reads as follows: "Pursuant to Section 36(2)(d) of the Correctional Services Act 1982, I hereby direct that you be kept separate and apart from all other prisoners until this direction is revoked.

In accordance with Section 36(6) of the Act, take notice that the grounds for your separation are as follows:

36(2)(D) In the interests of security or good order within the Correctional Institution." The present application seeks an order in the nature of certiorari quashing that decision and a declaration that the order made by the Chief Executive Officer is not lawful and not authorised by the statute. An order in the nature of mandamus that the plaintiff be returned to the mainstream section of the Institution was abandoned at the trial.

I should point out at the outset that I am not called upon the decide the merits of whether or not the plaintiff, as at 12 February 1997 should have been kept separately and apart from all other prisoners, or whether there is now justification for the continuation of the order, if properly made. The only matter which I am called upon to consider is the validity of the determination and whether it was affected by some extraneous considerations which the Act does not allow.

The affidavits filed on behalf of the plaintiff raised two grounds alleging invalidity of the determination. The first ground alleged that the previous orders were invalid, having been made without authority, there being no valid delegation to the persons who made the orders. It was said that, in a way which I will explain, this tainted the determination of the Chief Executive Officer. Secondly, it was claimed that the determination was not made for a reason permitted by s36 but rather pursuant to a policy to retain the plaintiff and the other prisoners involved in what is known as "G" Division pending their trial, either because of an agreed settlement with the union representing correctional service officers arising out of industrial action which followed the riot, or as a matter of policy in order to avoid possible industrial action if this core group or any members of it were returned to other divisions of the Yatala Labour Prison.

Section 36 of the Act reads as follows: "36(1) A prisoner must not be kept separately and apart from all other prisoners in the correctional institution except in accordance with this section.

(2) The Chief Executive Officer may direct that a prisoner be kept separately and apart from all other prisoners in the correctional institution if the Chief Executive Officer is of the opinion that it is desirable to do so

(a) in the interests of the proper administration of justice where an investigation is to be conducted into an offence alleged to have been committed by the prisoner; or

(b) in the interests of the safety or welfare of the prisoner; or

(c) in the interests of protecting other prisoners; or

(d) in the interests of security or good order within the correctional institution.

(3) A direction given pursuant to subsection (2)(a) has effect for such period, not exceeding 30 days, as may be specified in the direction.

(4) Any other direction given under subsection (2) has effect until revoked by the Chief Executive Officer.

(5) A direction cannot be given more than once pursuant to subsection (2)(a) in respect of the incident giving rise to the alleged offence.

(b) may be revoked at any time by the Chief Executive Officer.

(7) A copy of a direction given under subsection (2) must be served personally on the prisoner within 24 hours of being so given.

(8) Despite the fact that a direction under subsection (2) is in force in respect of a prisoner, the Chief Executive Officer may permit the prisoner to have contact with such other prisoners on such occasions as the Chief Executive Officer thinks fit.

(9) The Chief Executive Officer must, as soon as reasonably practicable after giving a direction under subsection (2), furnish the Minister with a report of the circumstances in which the direction was given.

(10) On receiving a report under subsection (9), the Minister may review the matter and may confirm or revoke the direction." Several points need to be made about that section. The discretion placed upon the Chief Executive Officer is expressed in broad terms, being dependent upon his or her opinion that it is desirable to make the order. However, it is at once limited by the consideration that must be given to the matters referred to in subparagraphs (a) to (d) inclusive. It is to be contrasted with s24(2) which vests in the Chief Executive Officer an absolute discretion to place any particular prisoner in such part of the correctional institution and to establish in respect of a particular prisoner such regime for work, recreation, contact with other prisoners or any other aspect of the day-to-day life of prisoners, as from time to time seems expedient to the Chief Executive Officer. That latter section was the subject of consideration by Perry J in Bromley v McGowan and Vardon (1994) 178 LSJS 1, where it was held that there were only very limited grounds on which the Court could intervene in relation to a decision made under that section. Whether the Court, in considering a determination under s36, is similarly limited, was not argued before me on this occasion. There can be little doubt, however, that, as in the case of s24(2), the exercise of power under s36 must be bona fide and not for a purpose unrelated to the grounds stated in subs(2). It was not suggested that the decision was not reviewable at all by this Court; cf Bromley v Dawes (1983) 34 SASR 73, dealing with the predecessor to this section in rather different form. Finally, it should be noted that a direction under subsection (2), other than for a reason referred to in paragraph (a), is of indefinite duration, and is not necessarily subject to any review by the Chief Executive Officer. For that reason, and for the serious consequences which follow for the prisoner, where a challenge of this nature is made, a Court will need to scrutinise carefully the reasons said to justify the determination, in order to ensure that no extraneous considerations have influenced the Chief Executive Officer in forming his or her opinion. I should add that Mr Kelly, the Deputy Director of Correctional Services, said in evidence that it was departmental policy to review such determinations from time to time, but it does not appear to be a requirement of the Act. It is not necessary for decision on this occasion, but a nice question might arise as to whether such a review which results in no change to the determination constitutes a further determination for the purposes of the section.

Also relevant to these proceedings are the provisions of s7(2) of the Act which enables the Chief Executive Officer, with the approval of the Minister, to delegate to any employee of the Department, any of the powers, functions, duties or responsibilities vested in, imposed on or delegated to the Chief Executive Officer under the Act.

The first ground of challenge to which I have referred, relating to the validity of the orders made prior to the one under challenge, can be relatively simply disposed of. Even if those orders or any of them were invalid, either because of some imperfection in the delegation to the General Manager or because they were made for improper reasons, that cannot of itself affect the validity of this order. The Chief Executive Officer who made the challenged order, Ms Vardon, said that it was unusual for such orders to be made by the Chief Executive Officer. They were generally made through the exercise of delegated powers by the General Manager of the correctional institution. She had been advised, however, that there may be some difficulty with the delegations in question, and for that reason she was advised to make the order herself. Ms Vardon, being the Chief Executive Officer at the time, was plainly empowered by the section to make the order herself. She was not acting under delegation. The reasons and justification for the order that she made will stand or fall by themselves. Any invalidity in the previous determinations could not be a reason to hold that, as a consequence, this determination was invalid. In any event, there is no evidence before me on which I could hold that the previous orders were invalid. There was no evidence of any formal delegation before me which would support the determinations made by a General Manager of the prison. However, there is a presumption of regularity on which I am entitled to act unless it is displaced by evidence. It is clear from Pertl v Kahl (1976) 13 SASR 433 at 436, where there was no proof of a delegation from the Federal Commissioner of Taxation, that the presumption of regularity includes a presumption of delegation where the power exists and appears to have been exercised, and also a presumption that a person acting in a public office has been duly appointed to the office, and is acting properly in the administration of the office. In short, there is no material before me on which I could properly hold that the previous orders were invalid.

If, however, the reason for making the order in question was merely for the purpose of validating a previous invalid determination or a determination that was thought to be invalid, and if it were made without consideration of the factors relevant to the exercise of the discretion under s36(2) of the Act, that would be an invalid exercise of the power. I will need to say more about the factors affecting Ms Vardon's determination in due course. As I have said, it was unusual for her to sign separation orders of this type. However, it appears that the possible invalidity of the previous orders may well have been the occasion which marked the making of the order and the reason for the order being made by Ms Vardon, as opposed to the General Manager of the institution. However, for reasons which will become apparent, I do not consider that that was a matter which had any bearing on the formation of Ms Vardon's opinion for the purposes of s36(2) of the Act. The reasons for which she made the order will depend upon an analysis of the evidence, particularly of herself and of Mr Kelly, and as to the considerations that were in fact taken into account when making the determination.

I turn to the second ground of challenge. Following the release of the hostages by the prisoners, a number of demands were made by prison staff on the management of the prison, and this resulted in the partial refusal to perform duties and the standing down of a large number of prison staff. It was acknowledged by Ms Vardon that there was considerable hostility on the part of prison staff to the hostage takers because of the injuries and damage for which they had been responsible, and because of the viciousness of the attack. Ms Vardon acknowledged that there was a "stand off" between the Department and prison officers as to the fate of the plaintiff and the others involved in the riots. However, Ms Vardon said (T30):

"... In fact, management took a very strong stand about who ran the prison and where a placement would happen, and, in fact, you may or may not recall that we stood down the prison officers at Yatala on that very principle, and the prison officers came back and accepted the position that management made decisions on that site."

Ms Vardon was not directly involved in the negotiations with the staff or their representatives. Mr Kelly was closer to the action, but he maintained that the industrial dispute was over a number of demands concerning security, procedures and equipment arising out of the hostage taking. He acknowledged that there was a concern on the part of prison staff about the possibility of the hostage takers being moved from "G" Division. He spoke of there being an understanding that an attempt to return the prisoners to the mainstream prison would await the outcome of the Court proceedings against them, but he also stressed that any such decision (as to whether or not they should be returned) was the General Manager's prerogative.

There were immediate negotiations for the return to normality after a lock down of the prison immediately following the riot. The document which was said to form the basis of agreement "to instigate unlock" at the prison and signed on 10 May 1996 included: "A. WRITTEN AGREEMENT WITH MANAGEMENT 1. Ring leaders

• Hostage takers - consultation on movement and placement.

It was suggested that that document required agreement of the staff before a decision was taken to move the prisoners in question - a suggestion which Mr Kelly denied. He only acknowledged that prison management would consult with staff if a decision had been made to move the prisoners, and not as to the decision to move them which both he and Ms Vardon maintained was purely the prerogative of management. I cannot find that there was any agreement that a decision to move the prisoners would not be made without consultation with the staff. That does not mean, however, that there was not a recognition on the part of management that, if the prisoners were moved, there might be industrial ramifications. The question is whether that had any bearing on Ms Vardon's decision.

On 23 July 1996 the plaintiff's solicitor received a letter from the Department for Correctional Services which purported to have come from the Chief Executive Officer but which had been signed by Mr Kelly on her behalf. The letter pointed out that the plaintiff was subject to an order pursuant to s36(2)(d) of the Act, and contained the following statement:

"It is anticipated that your client will remain under the current regime until the court process relating to offences arising from the incident has been completed." From that it was suggested that the real reason for the order of 12 February 1997 was based in part upon the fear of industrial action if the order were relaxed coupled with a policy decision that the prisoners in question should remain subject to the orders until their trial. Neither of these reasons, if they were the reasons, would in themselves satisfy the requirements of s36(2). Ms Vardon said in evidence, and I accept, that she did not write the letter and that she had not seen a copy of it until Monday 23 June 1997, a few days before the trial. It was not before her and she was not aware of it when she made her decision on 12 February, and she did not have regard to it. Mr Kelly acknowledged that it was his signature on the letter, but said that it had been written by another officer. He was not uncomfortable signing the letter, and he considered that the information in the sentence which I have quoted could have come from conversations with management of the Yatala Labour Prison. Both he and Ms Vardon said, and I accept, that there had not been any discussion between them about any such policy.

That brings me to the evidence of Ms Vardon as to the making of the order itself. She was aware of and had been fully briefed on the nature and consequences of the riot which had occurred in May. She was aware that the plaintiff was alleged to be one of the principal hostage takers. That had been a very serious incident, one of major concern to the security and good order of the prison. She was also aware from briefings she had been given from time to time that some of the hostage takers had been moved to other prisons in the State and that as a result there had been allegations of incitement to riot in those institutions by the same prisoners. At the time of making her determination she had before her the following report from Ms Bordoni, the General Manager of Yatala Labour Prison dated 11 February 1997: "REVIEW OF PRISONERS HELD IN YATALA LABOUR PRISON UNDER 36(2)(d) OF THE CORRECTIONAL SERVICES ACT

I have reviewed the circumstances under which Paul Page, who was involved in the Yatala Labour Prison hostage situation, has been detained under a Separation Order pursuant to Section 36(2)(d) of the Correctional Services Act.

In addition to Police charges following the Yatala Hostage situation, Paul Page is also charged with recently threatening a prison officer and his family. The threats occurred in December 1996 in front of witnesses. These include a member of the Sheriffs Office and Departmental escorting officers. He has pleaded not guilty before the prisons Visiting Tribunal and a date for the Tribunal is yet to be set.

His behaviour whilst separated has been extremely aggressive.

I am satisfied that the safety of my officers and the good order of the prison would be threatened if Mr Page was to be returned to the mainstream prison population and require that the appropriate Separation Orders under Section 36(2)(d) of the Correctional Services Act be issued to ensure that he remains separated whilst in Yatala Labour Prison." She had no material to elaborate on the information contained in the report, but the General Manager was, in her experience, a competent General Manager and one whose judgment she could trust. There were others in the Department whose judgment she might have questioned, but she did not feel it necessary in the case of Ms Bordoni. The threat referred to was relatively recent. The aggressive behaviour appeared to be continuing. She considered that what was contained in the report was sufficient for her to act, and accorded with the general background of what she knew about the group of hostage takers generally. Whilst none of the individual matters referred to in the report might, standing alone, have been sufficient to justify the order, she was entitled to and said that she did take into account all of the matters referred to in it together with the other background knowledge that she had of the plaintiff. That was all that she said she took into account. She said that she did not take into account any possible industrial ramifications of moving the plaintiff from "G" Division or of any intention or desire on the part of management (of which she was unaware) that the order should remain in place until the trial of the plaintiff. Whilst she accepted the advice of the possibility of some problem with the previous orders, she did not take them into account in making her own decision as to whether the order should be made.

I accept her evidence, and there is no other evidence that any other matters were brought to bear on the formation of her opinion at that time. The matters contained in the report plainly relate to the interests of security and good order within the institution, and were sufficient for her to form the opinion that it was desirable, in the interests of such matters, to direct that the plaintiff be kept separately and apart from other prisoners.

Following the making of the order, Mr Kelly sent a Minute to the Minister dated 18 February 1997. It was not firmly established that this was a report for the purposes of s36(9) of the Act, but no other such report was identified. It appears that a copy of the report of the General Manager to Ms Vardon was attached to the Minute. It referred to the making of the separation order on 12 February and the revocation of the previous order. The Minute contained the statement:

"Should he be transferred to another prison at some time in the future, his case will be reviewed." It was argued that the presence of that statement in the report to the Minister was further evidence of the intention to ensure that the plaintiff remained subject to the order until his trial. Ms Vardon appears to have been unaware of the content of the Minute. It was written by Mr Kelly. It may have reflected his understanding of the effect of the order, but it is equally clear that the statement forms no part of the order. It is also inconsistent with Mr Kelly's evidence that the status of persons the subject of such orders is reviewed periodically from time to time in any event. I find that there is nothing in the Minute to the Minister which is inconsistent with or which casts any doubt on the reasons for the making of the order as expressed by Ms Vardon in evidence. Those reasons were limited to the only matters that she was required to have regard to under the Act in making the decision, and accordingly there is no basis on which this Court can interfere with the decision.