Waiver of Legal Professional Privilege and Associated Material


The principle in Mann v Carnell (1999) 201 CLR 1 (‘Mann’) 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 (‘AWB’) – another leading case on implied waiver – Young J devoted several paragraphs to discussing waiver of ‘associated material’ relating to other waived communications (at [164]–[176]).

In both Zantran Pty Ltd v Crown Resorts Ltd [No 2] [2020] FCA 1024 (‘Zantran’) and Perth Airport Pty Ltd v Qantas Airways Ltd [No 2] [2021] WASC 342 (‘Perth Airport’), 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.

Zantran Pty Ltd v Crown Resorts Ltd [No 2] [2020] FCA 1024:

In Zantran, O’Callaghan J was required to determine whether there exists a recognised species of waiver called ‘associated material waiver’. Counsel for Zantran argued that passages from Young J’s judgment in AWB stood for the proposition that ‘a voluntary disclosure of privileged documents can result in a waiver of privilege over those documents and associated material’ and that ‘[t]he test applied to determine the scope of any waiver of associated material is whether the material that the party has chosen to release from privilege represents the whole of the material relevant to the same issue or subject-matter’. As put by O’Callaghan J in Zantran, it was submitted that ‘the voluntary provision of one privileged communication gives rise to a waiver of legal professional privilege over all other privileged communications relevant to the same issue or subject matter as the communication voluntarily provided’ (at [31]).

Counsel for Zantran relied on the following passage from AWB (inter alia): ‘Turning to the scope of any imputed waiver, it is well established that a voluntary disclosure of privileged documents can result in a waiver of privilege over those documents and associated material. The test applied to determine the scope of any waiver of associated material is whether the material that the party has chosen to release from privilege represents the whole of the material relevant to the same issue or subject matter’ (at [164] of AWB). Counsel for Crown argued that the only guiding principle for the waiver of legal professional privilege at common law is the inconsistency principle stated in Mann.

Justice O’Callaghan noted that the difference between the two submissions might be ‘more apparent than real’, but that ‘[i]n either case, the critical anterior question is to identify the relevant issue or subject matter’ (at [41]).

His Honour said that when there is an express waiver, ‘an issue arises about whether and to what extent privilege has also been waived with respect to “related” non-disclosed documents’, which might be described as ‘associated material’. However, O’Callaghan J rejected the submission that Young J’s judgment in AWB establishes a separate species of waiver relating to ‘associated material’ which expands the Mann principles (at [42]–[45]).

Perth Airport Pty Ltd v Qantas Airways Ltd [No 2] [2021] WASC 342:

Zantran was recently applied by Le Miere J in Perth Airport. In that case, Qantas sought production for inspection certain documents which record analysis and advice by Houston Kemp (an economic consulting firm) and Dr Mundy. Perth Airport claimed legal professional privilege on the grounds that the documents were communications between the advisers and Perth Airport or their solicitor that were prepared for the dominant purpose of giving or obtaining legal advice (at [9]). Justice Le Miere ultimately found that Perth Airport had, during negotiations with Qantas and other airlines, waived legal professional privilege in respect of certain advice from Houston Kemp, and that production of documents communicating that relevant analysis was necessary for disposing fairly of the proceeding (at [19], [27], [33]–[34]).

In relation to the scope of the order for production, Qantas also sought production of any material necessary to understand that analysis or which underpinned or influenced it, and any documents referred to in particular documents containing the analysis (at [28]). That is, Qantas submitted that the waiver extended to ‘associated material’ as discussed by Young J in AWB.

Justice Le Miere applied O’Callaghan J’s decision in Zantran, stating that ‘[t]he extent of any waiver is to be determined in accordance with the principles expounded in Mann v Carnell’ (at [32]). Accordingly, whilst Le Miere J noted that Perth Airport might be required to produce documents which are necessary to understand certain advice it received, this did not extend beyond the principles in Mann. For example, if Perth Airport had documents evidencing the knowledge and experience of Mr Houston (of Houston Kemp), it would not be inconsistent for Perth Airport to maintain confidentiality over those documents even though that knowledge and experience would no doubt underpin and influence the analysis he provided (at [33]–[35]).

In relation to any documents recording analysis undertaken by Dr Mundy, Le Miere J found that Perth Airport had not waived its privilege as it was not inconsistent for Perth Airport to state the Houston Kemp advice yet maintain confidentiality over the separate analysis by Dr Mundy (at [36]).


Together, Zantran and Perth Airport make it clear that the inconsistency principle from Mann is the sole principle relevant to determining whether legal professional privilege has been impliedly waived at common law. Whilst it may, in some instances, be inconsistent to retain confidentiality over certain documents associated with other waived communications, this will not always be so. Accordingly, Young J’s decision in AWB cannot be regarded as establishing a separate ‘associated material waiver’.

Some s 79C(2a) cases…

Find below a few short excerpts from (fairly) recent cases which considered issues relevant to s 79C(2a) Evidence Act 1906 (WA):

Zerjavic v Chevron [2020] WASCA 40 (in which a letter was found not to be a business record because it was a one-off document prepared by the business, rather than a document prepared in the ordinary course of that business):

‘The letter was a one-off piece of correspondence sent to the District Court in answer to a subpoena rather than a document prepared or used in the ordinary course of business for the purpose of recording any matter relating to the business. The primary judge was correct to reject the tender of the Sonic Health letter on the basis that it was not a business record.’ (at [146])

Collopy v CBA [2019] WASCA 97 (in which the point was made that s 79C(2a) allows for ‘a statement in a document that has been derived from a business record’ to be admitted, and that this description included screenshots of banking records):

‘… trial counsel objected to the admission of the screenshots on the basis that they were not admissible as business records because they had been prepared for the purposes of the litigation.

The screenshots themselves were not a ‘business record’ for the purposes of s 79C of the Evidence Act. They were, as Ms Lavater’s trial counsel observed, created in about October 2017 for the purposes of the trial. However, the information shown in the screenshots was derived from the Bank’s electronic business records in the manner described by Mr Kent. That is sufficient for the purposes of s 79C(2a)(a), which enables a statement in a document that has been derived from a business record to be admitted.’
(at [4]–[5])

Presilski v Shepherd [2021] WASC 100 (in which screenshots of Google Maps Timeline information fell under the s 79C(2a) business records exception):

‘… the Google Maps Timeline should be considered to have been generated by Google, from the underlying data recorded and stored by Google in its Google Maps system, in the ordinary course of its business of Google Maps, which, in the Google Maps Timeline functionality, tracks and registers the time and location of a user of a mobile telephone on a particular day. The appellant did not prepare the Google Maps Timeline, but rather accessed it…’ (at [143])

The State of Western Australia v Quartermaine [2020] WASC 458

This decision relates to a trial by judge alone before Hall J. The accused was charged with murder, and prior to the trial, admitted that he had unlawfully killed the victim. However, the defence argued that intent could not be proved beyond reasonable doubt (‘having regard to all the circumstances, including the intoxicated state of the accused’), and that therefore the accused could only be found guilty of a lesser offence ([4]).

During the trial, Hall J was required to determine whether the defence’s expert psychiatric evidence was admissible. This issue arose because the expert opinion was partially based on information which was not supported by sworn evidence. The issue is set out at [145]-[146]:

‘The accused elected not to give evidence. That was his right and no adverse inference can be drawn from that fact. However he did call expert evidence from Dr Victoria Pascu, a forensic psychiatrist.

Dr Pascu interviewed the accused at Hakea Prison and relied on information provided by him for the purpose of forming her conclusions. Some of the information provided by the accused reflected evidence that was otherwise available. However, the accused also provided Dr Pascu with some information, including in regard to his drug and alcohol usage generally and on the night in question, that was either not supported by the evidence or was inconsistent with it. This created an issue as to the extent to which Dr Pascu’s opinions were based upon information that was not supported by sworn evidence. An objection by the prosecution was taken to Dr Pascu’s evidence on this basis.’ (emphasis added)

In essence, the accused’s choice not to give evidence meant that he did not confirm on oath what he had said to Dr Pascu. This meant that some of the foundation of Dr Pascu’s opinion was not supported by any admissible evidence at trial, in that what the accused said to Dr Pascu was hearsay.

During the trial, Hall J decided that the evidence could be led, subject to any findings about weight, because Dr Pascu confirmed that it would be possible for her ‘to exclude the information that had been provided by the accused and to only rely upon the evidence before the court, including the accused’s interview with the police’ ([147]).

Justice Hall provided detailed reasons for his decision in the judgment, concluding that:

‘In this case prior to Dr Pascu being called she was asked whether it would be possible for her to put aside the information that was provided to her by the accused and whether she would still be able to give an opinion as to [the fact in issue]. She advised that she could do this. In these circumstances I concluded that Dr Pascu’s evidence would not be based entirely on inadmissible material and that insofar as she had partly relied upon any information from the accused which had not been confirmed on oath then that would reduce the weight to be accorded to her opinion.’ ([159])

As the opinion did not wholly rely on hearsay, it was still admissible. The extent of reliance on inadmissible hearsay ‘was able to be explored in cross‑examination and is relevant to the weight to be given to her opinion’ ([152]).

This decision is of interest for the practical application of the (sometimes unclear) ‘factual foundation’ or ‘factual basis’ rule – even the nature of which is still subject to some disagreement, as some regard it as a formal rule for admissibility and others regard it as more of a practical requirement in that an opinion without an admissible factual basis cannot be of any weight. The common law authorities relating to this rule are contradictory, so Hall J’s discussion of the principle is helpful to understand which authorities are to be preferred.

In this regard, his Honour cites at [158] (inter alia, and apparently with some approval) the following passage from Ipp J’s judgment in Pownall v Conlan Management Pty Ltd (1995) 12 WAR 370:

[E]xpert opinion based entirely on inadmissible evidence is itself inadmissible and there is no discretion to admit it. I form this view as to admit such an opinion would be to admit, indirectly, the inadmissible evidence itself. If an opinion, based solely on evidence that the court by law is required to exclude, is itself admitted, the inadmissible evidence would have some influence over the court’s decision. Such a result would defeat the purpose of the law that excludes the inadmissible evidence. If the primary facts on which the evidence is based are not admissible, the opinion is valueless and irrelevant and, in my opinion, should be excluded... It is only when the primary facts upon which the opinion has been based are established that the opinion should be admitted into evidence.

On the other hand, where the expert opinion is based only partly on inadmissible testimony and that inadmissible testimony can readily be ascertained and discarded, the opinion should be admitted subject to weight.’ (emphasis added)

The judgment:
The judgment was delivered on 11 December 2020 and can be accessed here. See especially paragraphs [145]–[159] for discussion relating to admissibility of the evidence.