Democrat deputy spokesman Yutthapong Charatsathian had urged the ministry to look into the deal, claiming Austrian manufacturer Steyr Daimler Puch was taken over by US-based General Dynamics Co in 2003 and as a result the Austrian ambassador may not have been authorised to sign off the deal.

Yutthapong also asked for a probe into why Andersner Oskar, trade adviser at the Austrian Embassy in Thailand, had reportedly attended a BMA meeting on December 24, 2004, to adjust the deal.

Apirak told a press conference yesterday that the Foreign Affairs Ministry should look into the legality of the so-called Agreement of Understanding and explain the peculiar document to the public.

He also said the panel set up to examine the contract, chaired by former National Institute of Development Administration rector Boonserm Veesakul, would submit its official report on the vehicles' unusually high prices to him this week. The panel has been investigating the deal since February.

But it would be the task of the Department of Special Investigation and National Counter-Corruption Commission to find out who was involved in the procurement, he said.

Apirak said the Office of the Attorney-General had been asked to determine if the fire-truck delivery to the Bangkok Metropolitan Administration (BMA) would be affected if Boonserm's panel found the prices were inflated. The office would also instruct the BMA on what to do next, he said.

Apirak would then pass on the results to the Interior Ministry as the deal was between the Thai and Austrian governments.

Representatives from Steyr Daimler Puch will be invited, if necessary, to discuss the probe's findings with the BMA, he said.

The panel will meet again on Thursday to conclude its findings before submitting the official report to Apirak, a source said.

The panel initially found that if a proper bidding panel had been set up, the BMA would have found a firm to sell the products at a far lower price. Taking into account inflation and other data, it was found the vehicles were overpriced by about Bt3 billion, the source said.