Pajun, the former secretary of Privy Council chief General Prem Tinsulanonda, is also a former member of the now-defunct National Reform Council.

Deputy national police chief Srivara Ransibrahmanakul yesterday said national police chief General Chakthip Chaijinda, not Prime Minister Prayut Chan-o-cha or his deputy Prawit Wongsuwan, had ordered police to file the complaint against Pajun.

“This matter is about the integrity of the Royal Thai Police,” he said. “The police risk losing the faith and confidence of the public and the allegation has tarnished the image of the whole police force.

“The national police chief issued the order since the allegation has no basis in fact or evidence.”

Srivara said he also filed a complaint seeking an investigation over whether Pajun had violated Article 123 of the Criminal Code.

Pol Maj-General Chaipol Chatchaidej, commander of the Planning Division, said Pajun may have also violated Article 14 of the Computer Act.

He said the Line chat messages involving the admiral indicated the alleged kickback required for each police rank.

If found guilty of violating the Computer Act, Pajun faces up to five years in jail and a fine of up to Bt100,000.

The defamation charge is punishable by up to two years in prison and a fine of up to Bt200,000.