A Tokyo-based firm paid some ¥100 million in rebates to people in three countries after winning tenders for projects financed by Japanese official development aid, sources said Thursday.

Japan Transportation Consultants Inc., paid the rebates to people involved in the projects in Vietnam, Indonesia and Uzbekistan over five years starting in 2008, the sources said.

If those involved include government officials, the rebate payments could run counter to the Unfair Competition Prevention Law, which prohibits bribes to foreign government officials.

The consulting firm has created a third-party panel to investigate the matter, the sources said.

Because the company failed to specify who was paid, local tax authorities have identified the payments as representing hidden taxable income and ordered the firm to pay a fine of ¥40 million, the sources said.