Pastina Thai filed a complaint with AEC chairman Nam Yimyaem accusing the subcommittee probing the scandal of threatening its representatives while being questioned, an AEC source said yesterday.

During recent questioning, members of the AEC Ua Athorn subcommittee told company employees they would be prevented from returning to Malaysia if their answers were unsatisfactory, the source said.

The complaint mentioned "several other threats" of legal action against employees, according to the source.

Ua Athorn subcommittee head Kaewsan Atibodhi confirmed the complaint but declined to speak about it.

Thai-Malaysian joint venture Pastina Thai has been accused of unfairly benefiting from bid rigging involving an Ua Athorn contract. It is linked with former social development and human security minister Watana Muangsook.

In a related development, the AEC subcommittee has discovered details of a deal between another contractor and the National Housing Authority (NHA), which operates the Ua Athorn project, according to another source familiar with the investigation.

It was discovered that on the last day of fiscal 2005 the NHA booked sales of land worth Bt600 million as revenue in spite of actually receiving just 20 per cent of that sum in the accounting period.

As a result, the NHA paid Bt52 million in bonuses to officials.

The Bt600 million became a cost because the authority had to repurchase the land upon completion of house construction, the source said.

The cost emerged in its accounts for the past financial year.

Kaewkwan said on Friday that his panel had found dubious money transfers from the NHA to one contractor. The agency first transferred money into the contractor's bank account less than five minutes before it received the payment for its land from the contractor.