
The affair concerns a Bt2-billion tunnel construction project, which was awarded by the Bangkok Metropolitan Administration (BMA) in 2003 when Samak was city governor.
"On behalf of the House committee, I will also fly to Japan before the end of this month to find out the truth," Democrat MP Chanchai Issarasenarak said yesterday in his capacity as the committee's vice chairman.
The tunnel project became embroiled in scandal last week after a news report revealed that a former executive of Japan's Nishimatsu Construction said he had paid bribes to Thai officials to get the contract.
The project was awarded to a joint venture between Italian-Thai Construction and Nishimatsu.
Chanchai said the former chairman of Nishimatsu had promised to cooperate fully with his committee.
"We will get evidence and documents relating to this scandal," Chanchai added.
Meanwhile, the Department of Special Investigation has agreed to begin a fact-finding probe into the scandal.
"It's not an investigation. It's a move to find out the truth first," DSI director-general Tawee Sodsong said yesterday.
In a related development, Bangkok city clerk Pongsak Semsant said a BMA probe into the same scandal had already resulted in a 1,000-page report.
Apirak is expected to receive the report this afternoon.
"We will also forward the information to the National Counter Corruption Commission," Pongsak said.