The discrepancy in the amount of secret state funds used by a former Foreign Ministry official to pay for hotel bills on prime minister's overseas trips is at least 500 million yen, not 310 million yen as the ministry has suggested, according to internal Foreign Ministry documents.

The gap in the money trail showed up on ministry records of hotel accommodations for 46 prime ministerial overseas trips from 1993 to 1999 that were handled by Katsutoshi Matsuo. The former Foreign Ministry division chief has been implicated for siphoning state money when he was in charge of arranging overseas accommodation.

The government has said Matsuo received 965 million yen from the Cabinet Secretariat to cover hotel bills beyond government-stipulated stipends.