The Fair Trade Commission searched the Japan Green Resources Agency and some of its 10 contractors Thursday as it opened a criminal probe into them on suspected bid-rigging over projects ordered by the quasi-governmental organization.

The FTC believes that officials of the agency, based in Kawasaki, and the contractors rigged bids for its projects, a violation of the Antimonopoly Law, by creating a list of successful bidders for each project at the beginning of every fiscal year, according to sources.

The officials under scrutiny have already owned up to the misdeeds "in principle" during questioning by the FTC, the sources said.