B. Legal Framework
6 Rule 24.01 of the Federal Court Rules 2011 (Cth) provides that a subpoena may be issued only with the leave of the Court. Section 31 of the Trans-Tasman Proceedings Act 2010 (Cth) (TTP Act) provides in so far as is presently relevant:
31 Subpoenas not to be served in New Zealand without leave
(1) If the proceeding is in an Australian court, the subpoena must not be served in New Zealand without the leave of the court.
...
(3) Without limiting the matters that the court may take into account in deciding whether to give leave under subsection (1) or (2), the court must take into account:
(a) the significance of the evidence to be given, or the document or thing to be produced, by the person named; and
(b) whether the evidence, document or thing could be obtained by other means without significantly greater expense, and with less inconvenience to the person named.
...
(emphasis in original)
7 Thus, s 31(1) of the TTP Act requires that leave of the court be obtained to serve the proposed subpoena in New Zealand and s 31(3) of that Act requires the Court to take into account, when exercising its discretion to grant such leave, the significance of the documents to be produced; and whether those documents could be obtained by other means without significantly greater expense, and with less inconvenience to the person named in the proposed subpoena. In Rauland Australia Pty Ltd v Law [2020] FCA 516 at [25] to [27], Stewart J made the following observations concerning s 31(3) of the TTP Act:
25 In relation to the test under the TTP Act, as has been observed, s 31(3)(a) does not provide any particular test except that the significance of the evidence to be given or the document or thing to be produced must be considered: Comeskey v New South Wales Bar Association [2015] NSWSC 12 at [15]; and Labruyere v Parsons Brinckerhoff Australia Pty Ltd (No 3) [2019] NSWSC 79 at [9].
26 The Court must also be satisfied under s 31(3)(b) of the TTP Act that the documents could not be obtained by other means without significantly greater expense, and with less inconvenience to the subpoena recipient. This requires consideration of whether the subpoena recipient needs to be compelled to provide the documents: Labruyere at [11].
27 The result is that the test for leave to serve a subpoena in New Zealand is more exacting than the test for leave to issue a subpoena. To start, there must be apparent relevance of the documents sought to be caught by the subpoena to the issues in the proceeding. In addition, the documents must be sufficiently significant to justify the expense and inconvenience likely to be caused by service of the subpoena. Greater expense and inconvenience would require greater significance of the documents in order to justify leave being granted. Moreover, if there is a less expensive and less inconvenient way of obtaining the documents, then leave might be refused on that basis.
(emphasis in original)
8 Both for the purposes of s 31(3)(a) of the TTP Act and in the exercise of the discretion to grant leave more generally, the extent to which the proposed subpoena has a legitimate forensic purpose is a central consideration. In this regard, in Wong v Sklavos; Satchell v Sklavos [2014] FCAFC 120; (2014) 319 ALR 378 the Full Court of this Court (Jacobson, White and Gleeson JJ) explained at 381 to 382 ([12]):
... The party issuing a subpoena bears the onus of demonstrating that the subpoena has a legitimate forensic purpose in relation to the issues in the proceedings: Santos Ltd v Pipelines Authority (SA) (1996) 66 SASR 38 at 52. A subpoena may be set aside if it requires the production of documents which do not have apparent relevance to the issues arising on the pleadings: Trade Practice Commission v Arnotts Ltd (No 2) (1989) 21 FCR 306; 88 ALR 90; Campaign Master (UK) Ltd v Forty Two International Pty Ltd (No 4) (2010) 269 ALR 76; [2010] FCA 398 at [39]-[40]; McHugh v Australian Jockey Club Ltd (No 2) [2011] FCA 724 at [13]; McIlwain v Ramsey Food Packaging Pty Ltd (2005) 221 ALR 785;[2005] FCA 1233 at [35]; Dorajay Pty Ltd v Aristocrat Leisure Ltd [2005] FCA 558 at [17]. Other cases have used different terminology, but with essentially the same effect, for example, by requiring that, viewed realistically, the documents sought have a bearing on an issue which is not unreal, fanciful or speculative (R v Barton (1981) 2 NSWLR 414 at 420), or that the material sought is reasonably likely to add in some way to the relevant evidence in the case (Spencer Motors Pty Ltd v LNC Industries Ltd (1982) 2 NSWLR 921 at 927), or that it be "on the cards" that the documents sought will materially assist the party at whose request the subpoena has been issued: Allister v R (1984) 154 CLR 404 at 414; 51 ALR 480 at 481; Tamawood Ltd v Habitare Developments Pty Ltd [2009] FCA 364 at [13] and [35]-[38].
9 In Seven Network (Operations) Ltd v Fairfax Media Publications Pty Ltd [2023] FCAFC 185, Wheelahan, Anderson and Jackman JJ referred to that passage, and then added (at [37]):
There is an ambiguity in that passage as to whether the words towards the beginning of the last sentence "essentially the same effect" are intended to mean that the three sets of terminology in the last sentence are all to the same effect, or whether those examples of terminology are to the same effect as the earlier concepts referred to, namely "a legitimate forensic purpose" and "apparent relevance". In our view, the latter interpretation is to be preferred. There is clearly a material difference between saying, on the one hand, that the documents sought have a bearing on an issue which is not unreal, fanciful or speculative or that the material sought is reasonably likely to add in some way to the relevant evidence in the case, and, on the other hand, that the documents sought will materially assist the party at whose request the subpoena has been issued. The first two of those expressions do not require that the documents sought will materially assist the party requesting that the subpoena be issued, and are neutral on that question. In our view, the passage indicates that the fundamental principle is that the party issuing a subpoena must demonstrate that the subpoena has a legitimate forensic purpose, and that it may be set aside if it is cast in terms which require the production of documents which do not have apparent relevance to the issues in the case.
(emphasis added)
10 Their Honours then referred, with approval, to the reasoning of the Court of Appeal of the Supreme Court of New South Wales in Secretary of the Department of Planning, Industry and Environment v Blacktown City Council [2021] NSWCA 145. At [38], their Honours stated:
That principle is consistent with the reasoning of the NSW Court of Appeal in Secretary of the Department of Planning, Industry and Environment v Blacktown City Council, which provides authority for the following propositions:
(a) the language of "tests" should be eschewed; whether a subpoena should be set aside depends on whether it involves an abuse of process, and it will be an abuse of process if it is not issued for a legitimate forensic purpose: Bell P at [60]-[61], with whom McCallum JA agreed at [98];
(b) it is not necessary to show that the documents subpoenaed will or will be likely to assist the case of the party that has issued the subpoena: Bell P at [57]-[58], Brereton JA at [86] and [96], McCallum JA at [98] and [100];
(c) it is sufficient to show that the subpoena can plausibly be seen to relate to an issue or issues in the proceedings or to cast light on such an issue, and the subpoena is not in other respects too vague or oppressive: Bell P at [57], McCallum JA at [98] and [100];
(d) put differently, it is sufficient to show that there is a reasonable basis for supposing that the material called for would likely add, in the end, in some way or another, to the relevant evidence in the case: Brereton JA at [89], with whom McCallum JA agreed at [100]; and
(e) it is sufficient to show that the documents sought are apparently relevant in the sense that it can be seen that the documents sought to be produced by way of subpoena will materially assist on an identified issue or that there is a reasonable basis beyond speculation that it is likely that the documents subpoenaed will so assist: Bell P at [65], with whom McCallum JA agreed at [98].
...
11 It was common ground that the applicants bore the onus of satisfying the Court that leave should be given.