Bank holding company Washington Mutual has asked a federal court for the power to make the Federal Reserve, the U.S. Treasury, and a long list of other parties turn over documents and witness interviews related to the bank's 2008 collapse.
Washington Mutual collapsed in September 2008 with about $307 billion in assets, and was acquired by JPMorgan for $1.9 billion in a deal brokered by the Federal Deposit Insurance Corp., or FDIC.
Seattle-based WaMu has said that price was much too low.
In papers filed Monday, WaMu said it wants to review e-mails and other materials to determine if suitor JPMorgan Chase undermined its value by disclosing confidential information that may have contributed to the nation's biggest bank failure ever.
WaMu has already launched a separate investigation of JPMorgan.
The request for a wider investigation was made in bankruptcy court, where a company can seek a so-called examiner who will conduct an independent investigation.