In Australian law, a general defence of public interest to a claim of breach of confidence is not available. The correct approach is the iniquity rule as stated by Gummow J in Corrs Pavey: information will lack the necessary quality of confidence only where the subject matter is the existence or real likelihood of an iniquity (crime, civil wrong or serious misdeed of public importance) and the confidence is relied upon to prevent disclosure to a party with a real and direct interest in redressing it. Where confidential documents are obtained by reprehensible means and no iniquity is disclosed, equity will grant full relief including delivery up, injunction against use, and striking out of pleadings tainted by the confidential material.
The full text is available to signed-in members, including the 23 later cases that cite this judgment.
4 of the 23 citing cases carry a classified treatment. How each court treated it is available to signed-in members.