An investigation into the controversial airship purchase deal can only be revived with new evidence, says National Anti-Corruption Commission (NACC) chairman Watcharapol Prasarnrajkit.
He was responding to Srisuwan Janya, secretary-general of the Association to Protect the Thai Constitution, petitioning the Office of the Auditor-General (OAG) to probe the case.
Mr Srisuwan said that if irregularities are found, the OAG must forward its findings to the NACC to punish Interior Minister Anupong Paojinda, the man who approved the purchase of the blimp when he was army chief.
- See also: Army above scrutiny
Mr Srisuwan's petition also targets former cabinet ministers of the Abhisit Vejjajiva government which approved the budget for the purchase and operation of the army airship. It went into service in 2009 to aid security in the far South.
The cabinet members include deputy prime minister Suthep Thaugsuban who oversaw national security and supervised the Defence Ministry.
Mr Suthep was subsequently accused by the Pheu Thai Party of failing to stop the army from buying the airship at an inflated price.
Claiming dereliction of duty, Pheu Thai petitioned the NACC to impeach Mr Suthep.
However, the NACC dismissed the request on Dec 24, 2015, saying it found no evidence to bear out the claim. Pol Gen Watcharapol said that if the investigation sought by Mr Srisuwan reached the NACC, it would have to consider whether the petitioner has uncovered new evidence which would support reviving the case against Mr Suthep.
"If the issue were to be brought back for consideration, there would need to be proof that new evidence exists," he said.
Meanwhile, Mr Srisuwan formally presented the petition to the OAG Monday, insisting the 340-million-baht airship aerial patrol project was not worth the budget.
He said the army had spent an additional 50 million baht a year on maintenance for the blimp, which pushed up the total cost to 700-800 million baht.
He said his petition singles out several targets for an investigation: Gen Anupong, the Abhisit cabinet which granted the army the budget to finance the airship project, the committee which inspected and received the airship and other state officials connected to the matter.
Pornchai Chamroonpanichkul, deputy auditor-general, promised to process Mr Srisuwan's request urgently, although he declined to give a deadline.
"I'm asking the OAG to get to the truth of the matter," Mr Srisuwan said.
"The information available [regarding the alleged problems with the project] should be even more solid than that in the submarine case," Mr Srisuwan said, referring to the navy's 36-billion-baht procurement plan for three new submarines.
The OAG conducted an audit of the planned procurement of the first submarine and said in May the project was above-board. It is one of three the navy intends to buy from China for 36 million baht.