The Foreign Ministry burned about 8,000 files of highly classified documents shortly before the nation's surrender on Aug. 15, 1945, according to Japanese diplomatic records declassified Thursday.
In early November 1945, the Supreme Commander for the Allied Powers General Headquarters began questioning senior ministry officials on the confidential materials.
Minutes of the senior officials' testimony showed that the ministry started organizing classified documents in late June 1945, "to respond to a possible U.S. military landing operation" on the mainland.
Between late July and early August that year, the ministry's archives division burned documents considered "relatively new and highly classified."
The ministry's telegram division disposed of the papers around Aug. 10-15, 1945, and told the GHQ later that about 8,000 files of classified documents were burned immediately before Japan's surrender.
Asked whether the papers were destroyed by orders from on high, the officials said the ministry held several meetings to discuss how to handle diplomatic records. The then vice foreign minister attended one of those meetings.
The officials also said the ministry did not compile a list of classified documents destroyed and that the materials were burned near a warehouse where they had been stored.
Other records showed that the ministry lost some 20,000 files in a fire caused by an air raid in May 1945.