The Board of Audit has uncovered 630 cases of improper use of government funds totaling more than ¥490 billion in the fiscal year that ended last March 31.
In its auditing report to Prime Minister Shinzo Abe on Thursday, the board said ¥490.7 billion was spent improperly or illegally. That was about ¥38.8 billion less than in fiscal 2011 but still the third-highest on record.
The single most expensive case highlighted in the report was a project administered by the Justice Ministry for maintaining prisons and other facilities that amounted to some ¥80.2 billion.
There were 470 cases that violated laws or regulations, up 30 percent from the previous year. The funds involved increased 2.8-fold year on year to ¥54.38 billion.
For the second year the board audited accounts related to reconstruction projects for areas affected by the March 2011 mega-quake and tsunami as well as decontamination and compensation payments related to the Fukushima nuclear crisis.
After reviewing 10 such cases, the report says 10 percent of the money appropriated for reconstruction work in fiscal 2011-2012 was spent on work that had little to do with disaster-affected areas.
Interest payments the government will incur as a result of helping Tokyo Electric Power Co. could reach around ¥79.4 billion, the board estimated.
The board also examined local measures to make facilities such as dikes, ports and government buildings more quake-resistant and tsunami-proof.
After a tunnel collapse on an expressway in Yamanashi Prefecture last December that killed nine people, the board also checked on local government efforts to inspect tunnels and bridges on expressways across the country.
The board found that many municipalities had put such inspections and maintenance work on the back burner or carried them out in an inadequate manner.
For the current fiscal year, the board plans to include checks on the situation in Iwate, Miyagi and Fukushima, the three prefectures hit hardest by the earthquake and tsunami, while continuing to examine cases related to Tepco.