The Australian Prudential Regulation Authority will not have to produce documents sought by plaintiffs in a class action relating to the timing and adequacy of disclosure by National Australia Bank.The plaintiffs have already obtained many documents from NAB (and also from Ernst & Young, the bank's adviser) that relate to the analysis and decision making by the bank on the portfolio of credit default obligations that the bank wrote down in a minor way in early 2008, and then wrote down heavily later in the year.Some of these documents tell NAB's side of its dealings with APRA over its original investment in the CDOs and the subsequent assessment of the credit risk.Justice Tony Pagone of the Supreme Court of Victoria ruled that Federal Parliament had "sought fit to confer upon APRA the power to approve disclosure and production [of documents] that is otherwise prohibited.""It is for APRA to decide whether to exercise the power and there is nothing to suggest that the legislature intended that the power be exercised whenever a court issues a subpoena upon the application of a party."On the contrary… the legislature intended to leave it to APRA to decide whether the power should be exercised."