Former commerce minister Boonsong Teriyapirom was sentenced to 42 years in jail for his involvement in corrupt government-to-government (G-to-G) rice deals.
His former deputy Poom Sarapol was sentenced to 36 years for the same offence.
Boonsong and Poom were among 15 others involved in facilitating the corrupt deals, while eight others, mostly rice millers, walked free.
The Supreme Court's Criminal Division for Holders of Political Positions handed down the ruling after it postponed the reading of its judgement on another rice case against former premier Yingluck Shinawatra to Sept 27.
A total of 28 people, including politicians and government officials, were charged with committing multiple offences in violation of the law on price collusion, the Criminal Code and the anti-corruption law, with reference to the rice scheme. Of them, two reportedly fled during the trial, postponing the reading of their sentences. Another, identified as Thanyaporn Chansakulporn, failed to attend the ruling, prompting the court to issue a warrant for her arrest.