https://www.employmentlawonline.com.au/able-record-conversations-managers-employees/#:~:text=The%20Surveillance%20Devices%20Act%201999%20(Vic)%2 0prohibits%20the%20communication%20or,your%20employer%20or%2 0fellow%20colleagues.
The Surveillance Devices Act 1999 (Vic) will not prohibit covert recordings of a private conversation if the party making the recording can show it was necessary for the protection of his or her lawful interests. A person’s “lawful interests” are broader than his or her legal interests, but they cannot be interests that are unlawful: Violi v Berrivale Orchards (2000) 99 FCR 580.
Generally, a mere desire to have a reliable record of a conversation or to gain an advantage in potential future litigation is insufficient. However, if a party is in a serious dispute with another party and the question as to what actually was said is likely to be significant in resolving that dispute, it is arguable recording those words is necessary to protect a lawful interest: Chao v Chao [2008] NSWSC 580.
The recording must be reasonably necessary to protect lawful interests in existence at the time: Marsden v Amalgamated Television Services Pty Ltd [2000] NSWSC 456. Making a recording because there is a possibility of some form of litigation in the future is not a lawful interest.