Prime Minister Prayut Chan-o-cha has ordered an investigation into the alleged involvement of senior Thai authorities in the Rolls-Royce bribery scandal, government spokesman Sansern Kaewkamnerd said on Saturday.
The government was not turning a blind eye to the issue and the investigation would find and punish wrongdoers, Lt Gen Sansern said.
"Old corrupt people must disappear, there must not be a new case, and corruption will not have a chance in any field," the government spokesman said.
He also said that a survey by the University of the Thai Chamber of Commerce found that corruption in the country was at its lowest level in the country in six years.
Gen Sansern said he did not think the revelations of corruption involving jet engine procurement by Thai Airways International (THAI) would have an impact on the country's standing in a closely watched corruption report by Transparency International later this month.
For one thing, the surveys to compile the annual ranking have already been completed. Gen Sansern also noted that British documents relating to the Rolls-Royce scandal indicate the last instance of dodgy procurement took place in 2005.
Transparency International ranked Thailand 76th out of 168 countries in the Corruption Perceptions Index in 2015, an improvement from 85th out of 175 countries in 2014. The higher the ranking, the worse the corruption.
The order from the prime minister was a response to calls for an investigation from the THAI labour union and the Anti-Corruption Organisation of Thailand (ACT).
The National Anti-Corruption Commission and the State Enterprise Policy Office will also investigate the matter.
The UK Serious Fraud Office (SFO) revealed this week that Rolls-Royce engaged in corruption or failed to prevent bribery in seven countries: Indonesia, Thailand, India, Russia, Nigeria, China and Malaysia.
The bribery case in Thailand involved the purchase of Trent 800 engines for Boeing 777 aircraft used by THAI during three periods between 1991 and 2005.
THAI management is investigating the cases, while PTT Plc has also begun an investigation into allegations of bribery by Rolls-Royce.
The state majority-owned oil and gas company is among a number of entities mentioned in a different Foreign Corrupt Practices Act case filed by the US Justice Department. The US documents allege that Rolls-Royce paid $11 million in "corrupt commission payments" between 2003 and 2013 to secure contract awards from PTT and subsidiary PTTEP for equipment and parts.
In the THAI case, a source at the national carrier said British authorities did not identify who was involved in the bribery, but only specified the periods in which the bribery took place. The SFO document appears to point to people at the national carrier as well as someone with air force connections.
According to a statement prepared in a British court, the scandal involved US$36.38 million (1.28 billion baht) in payments to "regional intermediaries".
Some of the money was for individuals who were "agents of the state of Thailand and employees of Thai Airways".
The source said the acquisition process involved people with decision-making powers, ranging from government ministers to board members and executives.