Breach of confidence is a common cause of action in matters involving intrusion of privacy. The doctrine is not statute-based but arises from common law (i.e. judge-made law) and equity.

To establish a claim for breach of confidence, based on the principles in Coco v A N Clark (Engineers) Ltd [1968] FSR 415, a plaintiff must prove that:

  1. The information is confidential;
  2. The information was imparted in circumstances importing an obligation of confidence; and
  3. There has been, or is threatened, an unauthorised use of the information to the detriment of the party communicating it.

This gives rise to further questions: under what circumstances is information considered confidential? When is an obligation of confidence imposed? And what does “detriment” mean? While the elements above were traditionally interpreted narrowly, case law has gradually broadened the scope of breach of confidence.

In the landmark case of ABC v Lenah Games Meats Pty Ltd (2001) 185 ALR 1, the first two limbs of the test were expanded. The Court began to use the terms “confidential information” and “private information” interchangeably. Subject to exceptions, the Court generally acknowledged that certain kinds of information (such as health and financial details) can readily be identified as private. Certain activities may also be considered private if, from the perspective of a reasonable person applying contemporary standards of morality and behaviour, they are expected to be unobserved.

As to the second limb of the test, the obligation of confidence also extends to third parties who come into possession of confidential information in circumstances where they know, or ought to know, how the information was obtained. In other words, if a third party obtains images or recordings of private activities and ought to have known that they were surreptitiously obtained, such constructive knowledge may be sufficient to impose an obligation of confidence.

A further development regarding the third limb of the test occurred in Giller v Procopets [2004] VSC 113, where the Court lowered the threshold of “detriment”. Unlike the traditional approach, which required proof of psychiatric injury, the law now recognises mental distress or embarrassment as an acceptable form of detriment when establishing a breach of confidence. This significantly broadened the doctrine, as psychiatric injury can be difficult to prove. With this development, breach of confidence arguably becomes a more accessible remedy for individuals seeking redress for a privacy violation.

The doctrine of breach of confidence continues to evolve and remains a widely used cause of action in privacy-related legal proceedings. While we look forward to seeing how it develops further, it’s also important to keep an eye on the forthcoming introduction of the tort of invasion of privacy under the Privacy and Other Legislation Amendment Act 2024, which will provide a new legal avenue for claims of privacy breaches.

Let’s explore that in the next article — stay tuned!

Ming Yip
Lawyer