Waiver of Legal Professional Privilege and Associated Material

The principle in Mann v Carnell (1999) 201 CLR 1 is that legal professional privilege over a communication is impliedly waived where disclosure and use of the communication is inconsistent with maintaining the confidentiality provided by the privilege. However, in AWB Ltd v Cole (No 5) (2006) 155 FCR 30 – another leading case on implied waiver – Young J devoted several paragraphs to discussing waiver of ‘associated material’ relating to other waived communications. In both Zantran Pty Ltd v Crown Resorts Ltd [No 2] [2020] FCA 1024 and Perth Airport Pty Ltd v Qantas Airways Ltd [No 2] [2021] WASC 342, it was argued that there was a waiver of associated material as described by Young J in AWB. Together, these decisions are helpful in understanding whether there exists an ‘associated material waiver’, and the relationship between the inconsistency principle and associated material. This case note first discusses O’Callaghan J’s decision on a point of law in Zantran, before considering its application by Le Miere J in Perth Airport.