The ‘Legitimate Forensic Purpose’ Limitation on Subpoenas

Written by Jourdain Wongtrakun.

A subpoena is a legal document that orders a person or entity to provide documents or give evidence at a hearing. They are used frequently in litigation to obtain information from entities that may be relevant to the facts in issue, but that are not in the possession of either party to the case.

However, there are limitations on this process. Before an order is granted for documents to be accessed, the party applying for a subpoena must identify a legitimate forensic purpose for the documents, and establish that the documents will materially assist the case “on the cards”. The phrase “on the cards” refers to a “reasonable possibility” that the documents will materially assist the case of the party (Walters v Perton [2019] VSC 356).

Parties are not permitted to engage in what is known as “fishing”, that is, to request documents hoping that something relevant turns up. The request must reasonably specify the documents or class of documents required. As Moffitt P states in National Employers’ Mutual General Association Ltd v Waind and Hill [1978] 1 NSWLR 372, “the only legitimate purpose of requiring the production, and permitting the inspection, of the stranger’s documents can be to add, in the end, to the relevant evidence in the case” (emphasis added).

When establishing whether documents are relevant, it is not sufficient for a party to simply assert that the documents they seek are relevant “on the cards”. As the Full Court of the Federal Court of Australia noted in Vissell & Vissell [2021] FamCAFC 76, there “must first be established a clearly particularised legitimate forensic purpose and then that it is “on the cards” that the documents sought would assist that identified purpose. If a subpoena is deemed to be unconnected to the identified forensic purpose, it is not relevant “on the cards”.

There are three types of persons that can object to a subpoena: the person to whom the subpoena is addressed, a party involved in the litigation, and any other person having sufficient interest in the documents being sought.

For the addressee, the limitation on legitimate forensic purpose exists to protect them against an undertaking that would result in significant expense to, and/or be extremely onerous for the person collating documents. A court is entitled to set aside or alter the orders to prevent this, particularly in circumstances where the documents sought are irrelevant to the litigation.

For the parties involved in the litigation, the limitation guards against unfair abuse of the litigation process.

Examples of other persons having sufficient interest in the request documents include but are not limited to those who may be identified in the documents, those whose actions are described in the documents, and those whose business or other interests may be affected by the evidence contained in the documents.