The head of a fact-finding panel checking the Bt6.68-billion Bangkok fire-vehicle scandal said there were solid reasons for not implicating Bangkok Governor Apirak Kosayodhin.

Chairman of the Assets Examination Committee's fact-finding panel Prasert Boonsri yesterday defended a decision to announce no wrongdoing by Apirak.

Politicians have accused the AEC of double standards for letting Apirak "off the hook" while pointing the finger at seven other officials - serving and non-serving.

"Apirak sent two letters objecting to the fire-vehicle purchase. But when he did so, he received four letters from then-interior minister Bhokin Bhalakula, his secretary Somsak Khun-ngern and then-deputy interior minister Pracha Maleenont.

"Somsak's two letters insisted Apirak open a letter of credit.

The Bhokin and Pracha letters threatened to hold Apirak responsible for any damages arising from a refusal to do so," Prasert said.

"Who was eager to open the letter of credit here?" Prasert asked.

Late last month, the AEC found grounds to believe that Bhokin, his then-deputy Pracha and then-secretary Somsak had arranged the deal to buy overpriced fire vehicles from an Austrian supplier, Steyr Daimler Puch.

It also found grounds for suspicion against former Bangkok governor Samak Sundaravej and Police Maj-General Atilak Tanchukiat, who heads the Bangkok Metropolitan Administration (BMA) Bangkok Fire and Rescue Department.

However, it found no grounds to implicate Apirak.

The AEC said the deal cost the country Bt1.9 billion.

The purchase dates back to 2004 when Bhokin as interior minister signed an agreement of understanding with the Austrian ambassador to Thailand to buy fire vehicles, fireboats and other fire-fighting equipment for the department.

Pracha and Somsak helped to prepare the agreement.

The Interior Ministry oversees the BMA.

Acting Bangkok governor Samak signed the purchase agreement just before he left office.

After becoming city governor and voicing concerns about the deal, Apirak opened the letter of credit that put the agreement into full effect.

Thai Rak Thai Party's acting spokesman Sita Divari questioned the AEC decision. "Is this double-standards?" Sita asked at a news conference.

He said Apirak played a part in the deal by opening a letter of credit and changing clauses in it that effectively allowed the supplier to deliver Thailand-made equipment.

"The deal was made to purchase equipment made in Europe," Sita said.

Prasert yesterday said separately an annex to the purchase agreement clearly stated equipment could be made in Thailand. He said Apirak proceeded as required by the agreement of understanding signed by Bhokin and the purchase agreement signed by Samak.

"I am ready to clarify my panel's decision," Prasert said.

"I am not protecting Apirak but I can't allow him to suffer because he's done nothing wrong," he said.

In response to a complaint from Bhokin that he was not permitted to testify in his defence, Prasert said the panel did not summon Bhokin because he submitted many documents related to his role in the case.

"We have read all his documents. We also read through his statements to the Department of Special Investigation," Prasert said.

Prasert said the panel would summon Bhokin now he had submitted a written request seeking an opportunity.