The Commonwealth of Australia & Anor v Commissioner Bret Walker SC & Anor

The Commonwealth of Australia and the Australian Securities and Investments Commission (ASIC) sought judicial review of a decision by Commissioner Bret Walker SC, who had been appointed as a special investigator under the ASIC Act 1990 (Cth). The dispute concerned the scope of the Commissioner's investigative powers, specifically whether he was entitled to access certain documents and information that the Commonwealth and ASIC claimed were protected by public interest immunity. The matter came before Keane J of the Federal Court of Australia.

The central legal issue before Keane J was whether the Commissioner, in conducting his investigation, was bound by the claims of public interest immunity asserted by the Commonwealth and ASIC. This required the court to consider the nature and extent of the Commissioner's statutory powers under the ASIC Act and how those powers interacted with the common law doctrine of public interest immunity. The court had to determine if the Commissioner's investigative mandate overrode the executive government's claim to withhold information in the public interest.

Keane J reasoned that the ASIC Act conferred broad investigative powers on the special investigator, designed to facilitate a thorough and unimpeded examination of the matters referred to him. His Honour held that the statutory scheme contemplated that the Commissioner would have access to all relevant information necessary to perform his functions, and that claims of public interest immunity, while generally valid, could not be used to frustrate the clear statutory purpose of the investigation. The court applied the principle that statutory powers, particularly those of a public investigative nature, are to be given their full effect, and that such powers are not to be unduly curtailed by common law doctrines unless Parliament has expressly provided for such a limitation. The court found that the claims of public interest immunity, as asserted in this instance, were not a sufficient basis to prevent the Commissioner from accessing the information he required.