The National Police Agency has discovered accounting irregularities tied to investigative expenses at 29 prefectural police forces, agency officials said Thursday.

The agency found the irregularities during a fiscal 2004 audit, carried out under a rule introduced in April 2004. It reported the results of the audit to a meeting of the National Public Safety Commission on Thursday.

The audit failed to unearth any cases of embezzlement, even though a number of such cases were exposed in Hokkaido and elsewhere in 2003, the NPA said.

The NPA conducted the audit from May 2004 through last month, interviewing 3,280 investigators and police officers who spent investigative budgets, the officials said.

The NPA did not audit the Hokkaido and Ehime prefectural police forces as they were undergoing separate audits in connection with embezzlement scandals, the officials said.

Irregularities found at the Metropolitan Police Department included incorrect dates and sums of money on accounting documents, the officials said.

The Osaka Prefectural Police had allowed unauthorized personnel to oversee documents that must be supervised by heads of departments or police stations, in violation of NPA regulations, they said.

Meanwhile, some police forces failed to reimburse some travel expenses, the officials said.