“It’s likely they accepted bribes,” he said, but the Office of the Auditor General would not identify them now.

Pisit said they were waiting for details requested from anti-corruption authorities in the US and UK.

The auditor general also said he the National Anti-Corruption Centre, which his agency is part of, would convene soon to discuss cooperation in regard to the bribery scandal.

The national flag carrier Thai Airways International (THAI) and energy giant PTT have been linked to bribes from the British company.

Inquiries by the United Kingdom’s anti-corruption authorities found that Rolls-Royce paid bribes to employees of those state firms as well as politicians in power on many occasions between 1991 and 2013 in exchange for lucrative purchase deals.

Rolls-Royce executives admitted to the UK’s Serious Fraud Office (SFO) that the company had paid Bt1.2 billion in bribes to THAI officials between 1991 and 2005, and Bt385 million to PTT officials between 2000 and 2013.

Meanwhile, Prime Minister Prayut Chan-o-cha will not invoke special powers under the post-coup interim charter to expedite investigation into the scandal, Government Spokesman Lt-General Sansern Kaewkamnerd said yesterday.

The PM has resolved that for the sake of appropriateness, the anti-|corruption agencies responsible should be allowed to do their work, the spokesman said.

Critics earlier suggested that General Prayut, who is also head of the National Council for Peace and Order (NCPO), should issue an order |exercising his power under Article 44 of the interim charter to expedite the ongoing probes.

“The prime minister is well aware of the general concern that the wrongdoers must be identified as soon as possible.

“But the government also has to take appropriateness into account. There are available steps for implementation and there are agencies that are directly responsible, such as the NACC and the OAG, and relevant laws,” Sansern said.

He was referring to the National Anti-Corruption Commission and the Office of the Auditor-General, which are separately investigating the alleged irregularities.

“There is no need to use Article 44 to deal with this matter,” the spokesman said, adding that going through normal legal process would allow the accused to fight the cases in a transparent and fair manner.

Prayut has issued many orders by invoking Article 44 to bypass certain existing laws in a bid to speed up his government’s work.

The spokesman said that Article 44 would be invoked only when it was necessary, such as when the existing steps were too complex and a delay would adversely affect public interest.

He also said that the prime minister was happy that public awareness against corruption seemed to have increased with mounting calls for the authorities to get the culprits and punish them. “However, the action must be taken carefully and prudently, which may take some time. We are confident that the responsible agencies will do their job to the best of their ability in the national interest.”

Meanwhile, an NACC source said the anti-graft agency might need to send its investigators overseas to interview witnesses living outside Thailand.

The source said the NACC’s fact-finding committee would not take too long to gather information regarding this scandal, as the SFO had agreed to provide necessary data to the Thai anti-graft agency.

Slide in corruption index ranking

The prime minister said he was not worried about a decline in Thailand’s ranking on the corruption perception index by the Berlin-based Transparency International, but he has instructed relevant agencies to pay heed to the assessment to fix any flaws, the government spokesman said.

Sansern said the PM had followed up the matter and instructed concerned agencies to look into weak points addressed in the report.

According to Transparency International’s 2016 corruption perception index report, Thailand scored 35 and was ranked 101st on the list for 2016 – a sharp drop from the previous year when the country scored 38 and was in the 76th spot.

The report said the decline partly stemmed from the current repression, the lack of independent oversight, and the deterioration of rights, which weakened confidence in the country.

Sansern however, defended the drop in the score, saying it is only three points lower that that of the 2015 assessment, and the fall in the rank is probably the result of more countries being assessed.

He said the PM had ordered |concerned agencies to look at weaknesses such as the perceptions of |businessmen in regard to state officials and corruption cases, state procurement, and others areas where Thailand scored low in the assessment.