A new deputy agriculture minister has dismissed reports about his past criminal record, claiming he was innocent and the opposition was trying to discredit him.

Capt Thammanat Prompao is probably the most controversial figure in the new cabinet due to his record. 

He was said to have been convicted and jailed in Australia in a case involving heroin, and was linked to a murder case of an academic whose body was dumped in Si Sa Ket in 1998, but later acquitted. His involvement in the latter case led to the removal of his military rank but it was reinstated later.

The former army officer told Thai media on Thursday there was a misunderstanding about his case in Australia 30 years ago, when he was a second lieutenant.

"I didn’t import, produce or deal heroin. While on vacation in Sydney, I was properly cleared by immigration. But I was unfortunate to have been in the same place at the same time as some drug offenders."

"I was later deported to Thailand because of a policy by the then Sydney mayor, who didn’t welcome Asians who formed groups and had no permanent residence." 

He insisted he was not deported to serve time for a drug sentence as claimed by some reports. 

He claimed he knew the source which spread false rumours against him and told reporters it was not in his party.

Deputy Prime Minister Wissanu Krea-ngam said he could serve as minister despite his conviction since the disqualification only applies to Thai court rulings.

Last year, police also found him to be one of the recipients of the shares of DNA, a company involved in a 797-million-baht bitcoin fraud.

Capt Thammanat was formerly with Pheu Thai. After the coup, he was one of the targeted influential figures on the list of the National Council for Peace and Order. His house was searched several times as he reportedly ran an illegal debt-collection business. 

Capt Thammanat changed his name a few times from Manat to Pajara and then Thammanat.