In an interview with Nation Multimedia Group digital journalist Suthichai Yoon on Facebook Live, former NACC commissioner Medhi Krongkaew questioned why the case was not being pursued by the anti-graft agency.

He said there was clear evidence that the bribe recipient was an executive with the Thai Rak Thai Party, including during Thaksin Shinawatra’s tenure as premier.

“We even know the name of this person,” said Medhi, who claims to have received first-hand information from the US Securities and Exchange Commission (SEC) while gathering evidence regarding another corruption case.

However, the NACC has not taken action on the Diageo case, in which money was allegedly paid to the senior official to influence the Thaksin government’s decision to lower tariffs on imported spirits, including Johnny Walker Black Label.

In one of his radio broadcasts, Thaksin publicly endorsed determining import duties based on volume rather than the value of liquor for sale in Thailand.

Details released by the SEC show that instalments of US$12,000 (Bt420,000) had been paid over 49 months to the Thai official.

Diageo settled its case in the US by paying a fine of nearly Bt500 million for violating the foreign corrupt practices law, but the case has gone nowhere in Thailand over the past five to six years, Medhi said.

He added that after retiring from the agency, he was not able to follow up on the case, while US authorities had decided not to take criminal action against the company after it paid the hefty fine.

He said that he would certainly have pursued the case if he had remained with the NACC.

Medhi said the case was similar to the Rolls Royce-Thai Airways scandal, in which millions of baht was paid for the sale of aircraft engines.

In the Diageo case, SEC documents also show that two meetings had been held between senior Diageo officials and Thaksin in 2005.

Medhi added that the Rolls-Royce case was a major turning point in tackling cross-border bribery cases as well as cooperation between Thai and foreign anti-graft agencies.

He said most NACC commissioners were committed to their jobs, but the agency had a shortage of personnel who were well-versed in English so cross-border cases were a challenge. He said only about 10 officials could fully understand English-language legal documents provided by their foreign counterparts.