From the US National Archives:
100,000 Pages Declassified in Search for Japanese War Crimes Records
New IWG Volume and Records Guide on Japanese Records Now Available
The Nazi War Crimes and Japanese Imperial Government Records Interagency Working Group (IWG) announces the availability of 100,000 pages of recently declassified records as a result of a search for files relevant to Japanese war crimes. In addition, the IWG presents a new reference book, Researching Japanese War Crimes Records: Introductory Essays and an electronic records finding aid that will help researchers locate and use the thousands of new and extant files in the National Archives related to the war in the Pacific.
The declassification is a result of a thorough investigation by several U.S. government agencies for classified records remaining in their files, pursuant to the requirements of the Nazi War Crimes and Japanese Imperial Government Records Disclosure Acts. The declassified records include a range of materials from the Office of Strategic Services (OSS), CIA, the State Department, Army Intelligence, FBI, and other agencies, and cover many aspects of the Pacific conflict and postwar relations between the United States and Japan. In general, however, only a small portion of these records specifically pertains to Japanese war crimes. The records are open and available at the research room of the National Archives at College Park, Maryland. ...more..
Direct link to online highlights from the archives.