CPB Contractors Pty Ltd and Hansen Yuncken Pty Ltd v State of SA

This appeal concerned a dispute between CPB Contractors Pty Ltd and Hansen Yuncken Pty Ltd (the Builder), an unincorporated joint venture, and the State of South Australia. The dispute arose in the context of two parallel arbitrations concerning the design and construction of the new Royal Adelaide Hospital (nRAH). The Builder sought the production of certain documents from the State, which the State resisted on the grounds of public interest immunity and parliamentary privilege. The primary judge had upheld the State's claims of public interest immunity in relation to a significant number of these documents and refused to order their inspection.

The legal issues before the Full Court of the Supreme Court of South Australia were whether the primary judge erred in upholding the State's claims of public interest immunity over certain documents and in refusing to inspect most of them. The appeal specifically focused on claims of public interest immunity concerning less than 100 documents, which had been categorised by the State as "Cabinet documents" or documents whose disclosure would reveal information provided to Cabinet.

The Court considered the principles of public interest immunity, particularly in relation to Cabinet documents, referencing authorities such as *Alister v The Queen* and *Commonwealth v Northern Land Council*. The primary judge had determined that the documents, or parts thereof, were properly put before Cabinet for its deliberations on budgetary decisions and directions concerning the nRAH Project Steering Committee. While the State did not defend a broad statement made by the primary judge regarding all documents, the Court found that, viewed as a whole, the primary judge's reasons indicated a view that the disputed documents were, to varying degrees, within the scope of public interest immunity as Cabinet documents. The Court ultimately dismissed the appeal.