Niphon Bunyamanee, a former deputy leader of the Democrat Party, has been sentenced by a court to nine years in jail after he was found guilty of committing malfeasance during his term as president of the Songkhla provincial administration organisation (PAO) in 2013.
He was also stripped of his right to stand in elections for five years.
The sentence was handed down by the Central Criminal Court for Corruption and Misconduct Cases on Thursday.
Niphon, who stepped down from his deputy interior minister role in the previous government during the trial, was found guilty of violating Section 157 of the Criminal Code.
The court said he refused to pay Ponlavit Tech Plus Co 52 million baht for road maintenance vehicles the Songkhla PAO had called for by tender in 2013.
Niphon was investigated by the National Anti-Corruption Commission (NACC), which found grounds against him and forwarded the case to the court.
During the NACC investigation, Niphon said he could not pay Ponlavit Tech Plus Co because the bidders were found to have forged documents and indulged in price collusion, causing damage to the PAO.
The court had issued arrest warrants for all bidders, including the winning company and its subsidiaries. However, most of the suspects had fled abroad. Those who were caught have reportedly been indicted in court.
Niphon was granted bail on Thursday after paying 200,000 baht, but he is not allowed to travel abroad. He said he would consult with his attorney to appeal the court's decision.
Ponlavit Tech Plus Co filed a lawsuit against him in 2013 when he refused to pay the 52 million baht. The Songkhla Administrative Court in 2017 ruled in the company's favour.