TOKYO (REUTERS) - A former employee of Universal Entertainment Corp filed a criminal complaint against Kazuo Okada, the Japanese firm's billionaire founder, alleging he ordered the payment of bribes to advance a still-unfinished casino project in the Philippines.

Mr Takafumi Nakano submitted his complaint to Tokyo District Public Prosecutor's Office in late May. It was not clear if the prosecutors' office, which declined to comment, would investigate his claims.

Mr Nakano has made similar claims in an ongoing civil defamation case against his former employer. The criminal complaint marks the latest salvo in a long-running legal battle between Mr Okada and three former employees over US$40 million (S$50 million) in payments made in 2010 that have been the subject of separate investigations by the US Federal Bureau of Investigation, the Nevada gaming regulator and the Philippine government. If US and Philippine authorities decide there is evidence of wrongdoing, Mr Okada and his companies could face prosecution for violation of anti-bribery laws in those countries. The Nevada regulator could impose sanctions impacting various licenses in the state, including to manufacture and distribute slot machines.

Mr Okada and Universal Entertainment have filed lawsuits against the three former staff, accusing them of transmitting a portion of the money without proper authorisation. In court filings all three men have said they were acting on Mr Okada's orders.

In the complaint, Mr Nakano said Mr Okada ordered that the bulk of the money be paid to Rodolfo Soriano, a consultant with close ties to Efraim Genuino, then head of the Philippine gaming regulator, with the aim of securing tax and foreign ownership concessions for the US$2 billion casino Universal is building on Manila Bay.

Universal did not respond to a request for comment. Mr Soriano and Mr Genuino, who have not been charged with any wrongdoing, could not be reached for comment.

"The only conclusion is that US$30 million was paid as bribes to Genuino or to other public officials" who could influence the relaxing of foreign ownership regulations and Peza recognition, Mr Nakano wrote in his complaint, referring to a tax-light economic zone in Manila.

The lifting of restrictions on foreign ownership of casinos and the approval to operate in Peza were granted in 2010 around the time the payments were made to two companies controlled by Mr Soriano. Universal has denied any connection and says it has conducted its business in the Philippines lawfully.