Government auditors have found another potential waste of taxpayers' money in the Social Insurance Agency, which has come under fire over the past few years for budgetary oversights, Board of Audit sources said Sunday.

This time, an audit has found potential carelessness in contracts the agency signed with NTT Data Corp. and two other companies to develop and manage online computer systems used for paying pensions and collecting insurance premiums.

The audit board suspects the agency did not check the contracts and how the system, linking over 300 agency offices nationwide, is actually managed, the sources said.

The audit found that a flat rate was applied in the contracts in salary payments to system engineers and software programmers despite differences in the nature of work supplied, they said.

Some computers and other equipment used for the system were also different from those stipulated under the contracts, the audit showed.

"We unified the unit rate for personnel costs for easy computation," an official of the Social Insurance Agency said. Estimates were made by taking account of unit rates for different duties, the official added.

In fiscal 2003 alone, the agency paid around 100 billion yen to the three companies -- 80 billion yen to NTT Data, 3 billion yen to Hitachi Ltd. and 17 billion yen to Japan Electronic Computer Co. The contracts were signed without competitive bidding.