Breach of Confidence

Video overview by Nicolas Suzor on breach of confidence.

  • Equitable doctrine
    • Does not confer a property right.
    • Binds the conscience of a person receiving a secret.
  • Many uses
    • Trade secrets, know-how, customer information, commercialisation information.
    • Non-contractual remedy to protect development of ideas / patentable information.
    • Quasi-privacy right.

Benjamin Odman - Breach of confidence and personal privacy


  • Three main elements:
    • Confidential information;
    • Disclosed in circumstances of confidence;
    • Actual or threatened disclosure.
  • Fourth element for Government information:
    • Disclosure is against the public interest.

Element 1: Quality of Confidence

  • Requirement of secrecy
    • Once information enters the public domain, the quality of confidence is lost.
  • Relative secrecy is sufficient (Gee v Day).
  • Information can be disclosed if recipient is under an obligation of confidence (NDA).

Ansell Rubber Co v Allied Rubber Industries [1967] VR 37

  • Trade secret case. Machine patented but improvements were not.
  • Have regard to:
    • the extent to which the information is known outside the owner's business;
    • the extent to which it is known by employees and others involved in his business;
    • the extent of measures taken to guard the secrecy of the information;
    • the value of the information to him and to his competitors;
    • the amount of effort or money expended by him in developing the information; and
    • the ease or difficulty with which the information could be properly acquired or duplicated by others.

Argyll v Argyll [1967] Ch 30

  • Duchess of Argyll obtained an injunction to prevent disclosure of marital secrets by her ex-husband.
    “Secrets […] relating to her private life, personal affairs or private conduct, communicated to the first defendant in confidence during the subsistence of his marriage to the plaintiff and not hitherto made public property.”

Commonwealth v Fairfax (1980) 147 CLR 39

  • Leaked information was embarrassing to Cth govt
  • Once the information was published, it lost its character of confidentiality.
    “The sales of the book already made, including those made to Indonesia and the United States, the countries most likely to be affected by its contents, and the publication of the first instalment in the two newspapers, indicate that the detriment which the plaintiff apprehends will not be avoided by the grant of an injunction. In other circumstances the circulation of about 100 copies of a book may not be enough to disentitle the possessor of confidential information from protection by injunction, but in this case it is likely that what is in the book will become known to an ever-widening group of people here and overseas, including foreign governments.” (54, Mason J)

AG v Guardian (No 2) (Spycatcher)

  • Former MI5 agent moved to Tasmania to escape UK law and write a book revealing some MI5 secrets.
    • British could not enforce UK legislation here.
    • Information was leaking rapidly.
    • Injunction to prevent further publication not available.

Sam Turner on Spycatcher (breach of confidence)

Cam McCall on Spycatcher (breach of confidence)

Element 2: Circumstances give rise to an obligation of confidence

  • Where the reasonable recipient would believe that information was given in confidence.
  • Can also include:
    • Information received pursuant to a contract (Bate's Case);
      • Information received in a course of relationship – employment, contractual, or fiduciary;
      • Could extend to a third party if third party knows or ought to know that the information is confidential;
      • Surreptitiously obtained information.

Coco v A N Clark (Engineers) [1969] RPC 41

  • Whether a reasonable person in the position of the recipient would have recognised that the information was given in confidence (Megarry J).
    • Contractual negotiations around a new moped engine.
    • Circumstances imposed obligation of confidence, but information was not sufficiently novel.

AG v Guardian (No 2) (Spycatcher)

  • Duty not limited to relationships:
    "also to include certain situations, beloved of law teachers, where an obviously confidential document is wafted by an electric fan out of a window into a crowded street, or when an obviously confidential document, such as a private diary, is dropped in a public place, and is then picked up by a passer-by” (Lord Goff, in obiter)

Douglas v Hello! [2005] EWCA Civ 595

  • Douglas' negotiated to commercialise the photography rights at their wedding.
    • Wedding had the quality of confidence.
    • Photographs obviously taken by a surreptitious gatecrasher.
    • Circumstances satisfied the equitable obligation.

Element 3 - Actual or Threatened Use

  • Use without consent.
  • Use beyond scope of limited purpose.
  • Unauthorised use of the information.
  • Intention to breach is not an element.
  • Detriment. Sufficient to show:
    • Loss of commercial advantage;
    • Ability to exploit;
    • Embarrassment;
      • Exposure to discussion and / or criticism.
  • Information can be disclosed where there is just cause or excuse.
    • Three main views:
      • Iniquity;
      • Disclosure of wrongdoing or for public safety of community (strongest approach);
      • Balance of the public interest (UK approach, not accepted in Australia).

Paris Hamrey - Breach of Confidence and the Public Interest

Corrs Pavey Whiting and Byrne v Collector of Customs (Vic) (1987) 10 IPR 53

  • Applicant represented patentee; sought documents under FOI relating to importation of patented drug.
  • Customs declined, citing breach of confidence.
  • Gummow J, dissenting, discussed the existence public interest test, suggesting that it was better thought of as:
    • Equity barring the plaintiff on the basis of unclean hands; and
    • No quality of confidence in equity for information that shows crimes, wrong or misdeeds of public importance.

Naomi Campbell v Mirror News (2004)

  • Campbell's attendance at Narcotics Anonymous may have had the necessary degree of confidentiality (doubted on appeal).
  • Confidence was lost by Campbell's deliberate courting of the media and an anti-drug reputation.
    1. Public interest test.


  • Injunction:
    • Interlocutory;
    • Permanent.
  • Damages, account of profits.
  • Usually plaintiff seeks an injunction.
    • Beware the Streisand effect.
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