Japan's Nishimatsu Construction Co planned to offer about 350 million yen (US$3.8 million) in bribes with its joint venture partner in Thailand to then Thai government senior officials to win a 2003 tunnel construction project, sources said Thursday (January 15).

Nishimatsu, a Tokyo-based second-tier general contractor, and its Thai partner reportedly prepared a total of 480 million yen ($5.3 million) for bribery maneouvering, with Nishimatsu contributing about half the amount.

The Tokyo District Public Prosecutors Office on Wednesday (January 14) arrested a former vice president of Nishimatsu Construction, Keiji Fujimaki, 68, on suspicion of smuggling 70 million yen into Japan from abroad.

The public prosecutors special investigation squad asked Thai prosecutors to cooperate in investigating the case as a violation of the Unfair Competition Prevention Law, as Nishimatsu and its Thai partner are suspected to have committed bribery, the sources said.

The Bangkok Metropolitan Administration in the Thai capital commissioned the public works project to construct a 3.5km tunnel to let water out of a canal in central Bangkok as a flood-prevention measure.

Nishimatsu and its local joint venture partner won the flood prevention tunnel construction project contract for about 7 billion yen ($77.5 million) in July 2003.

Nishimatsu held talks with its Thai partner and planned to offer bribes to BMA and Thai government officials to win the contract, the sources said.

Each company reportedly contributed about 240 million yen ($2.6 million) to the bribery fund.

Nishimatsu and its Thai partner also reportedly decided how to apportion the 350 million yen ($3.8 million) in bribes among several senior Thai officials, and to give the remaining 130 million yen ($1.4 million) to local bodies responsible for monitoring bribery activities.

Kazuhiko Takahara, 63, a former deputy manager of Nishimatsu's overseas operation department, was rearrested Wednesday on suspicion of violating the Foreign Exchange and Foreign Trade Law.

More than 400 million yen ($4.4 million) was used to win the contract for the Bangkok construction project, the public prosecutors special investigation squad quoted Takahara as saying.

Fujimaki admitted to the allegation that he instructed Takahara to bring 70 million yen illegally into Japan, sources said.

Fujimaki is believed to have ordered his subordinate, Takahara, to bring the money without declaring it to customs authorities on five different occasions to Japan from Hong Kong and other locations from February 2006 to August 2007.