MANILA, Philippines -- The winning bid of an American firm to supply the military with six night-capable attack helicopters worth $29 million could be scrapped, if an investigation determines the bidding was rigged, a spokesman for Defense Secretary Gilberto Teodoro Jr. said.

Teodoro tasked Defense Undersecretary Ariston Delos Reyes to investigate the bidding after a losing bidder, Poland's PDL Swidnik S.A., complained the bidding "favored" Asian Aerospace Corp., the local partner of Boeing Co.'s McDonnell Douglas, Teodoro's head executive assistant, lawyer Nelson Victorino, said.

"It's more of a fact-finding investigation, a committee that will look into all available documents and get sworn statements?to assist him in making a decision on whether [or not] to scrap this project altogether," Victorino told reporters in Camp Aguinaldo.

"Secretary Teodoro really wants transparency, regularity, and fairness in all these bidding processes," he added.

If scrapped, Victorino said the delivery of the MG-530F helicopters would be delayed for three months. The first batch of deliveries would have started this month, and the delivery period covers 12 months.

"The modernization program is moving forward, of course this will be a setback but only temporary," the spokesman said.

Depending on the outcome of the initial inquiry, Victorino said a separate investigation of the defense department?s bids and awards committee, which oversaw the bidding, could be launched.

He said the contract has not been awarded to Asian Aerospace since it has yet to past "post-qualifying" tests. A team was sent to the US to test fly the MG-530F but no units were available. Instead, the team flew an MG-520, a similar aircraft with a relatively weaker engine.

The BAC disqualified PDL Swidnik from bidding for the contract for failure to submit certain documents. A third bidder, Italy's Augusta, also lost out to Asian Aerospace, Victorino said.

The Polish firm wrote to President Gloria Macapagal-Arroyo and Teodoro alleging the MG-530F choppers were overpriced and could not meet the 3,000-pound payload requirement set by the BAC, Teodoro?s spokesman said.

But in the test flight of the MG-520, which is currently in the AFP arsenal, the pilots concluded by "inference" that it could withstand the required payload, since the unit they planned to purchase would run on a stronger engine, Victorino said.