Deputy Agriculture and Cooperatives Minister Thamanat Prompow has shown what he claimed was proof after fresh allegations his PhD might be fake.

The minister on Thursday evening showed reporters a copy of his dissertation and transcript.

“I received the degree from US-based California University Los Angeles, not from the Philippines,” he said.

CSI LA, a Facebook responsible for bringing a probe on Deputy Prime Minister Prawit Wongsuwon’s luxury watch collection, brought up the issue after it checked his educational records on the House website.

They show he holds a bachelor’s degree from Chulachomklao Royal Military Academy and two master’s degrees — in Buddhism from Mahachulalongkornrajavidyalaya University and MA programme in political science from Ramkhamhaeng University.

But the degree that raised questions is his PhD. For a moment, the House database showed he holds a  doctor of philosophy degree in public administration from "Calamus International University".

CSI LA claimed the university was not accredited and did not exist.

The House database website was later changed after the news broke to show he obtained the same degree from California University FCE, whose website carries warnings against a fake online institution bearing the same name in the Philippines.

Capt Thamanat, who claimed someone had hacked into the House system to change his data, said California University FCE was accredited, with a global network.

Discussing his conviction in Australia, Capt Thamanat told the House on Wednesday he had never confessed to smuggling, dealing or importing drugs, and challenged anyone who said otherwise to produce evidence when he did it.

The Sydney Morning Herald again challenged his claims on Thursday.

"Contradicting Thammanat’s statement to Parliament on Wednesday, the NSW Court of Criminal Appeal judges stated: 'Each of these applicants [Manat and Sorasat] pleaded guilty to being knowingly concerned in the importation of a commercial quantity of heroin'," read the article.

Prime Minister Prayut Chan-o-cha said Capt Thamanat did well in his explanations to the House and said screening the qualifications of a minister was done by a team who then submitted the results to him so he couldn’t be expected to know everything.