Former commerce minister Boonsong Teriyapirom and 18 others pleaded innocent in the government-to-government rice-sales corruption case Monday.
Two others charged in the case -- Weerawut Wajjanapukka, former secretary to Mr Boonsong, and Suthee Luanthaisong -- failed to appear and never have applied for bail. The court issued arrest warrants for the pair.
Mr Boonsong and other defendants are allowed to submit written testimony to the court by Aug 31, and the court set Sept 29 for the first examination of evidence.
The 21 individuals were indicted March 17 on charges of committing and supporting malfeasance in violation of the Criminal Code and competitive-bidding and anti-corruption laws.
Prosecutors alleged they colluded to help two Chinese firms not authorised by the Chinese government to undertake G2G deals with the Thai government to buy rice from stockpiles generated by the Yingluck Shinawatra administration's pledging scheme.
Each in the group, which comprises three politicians in the Yingluck government, three civil servants and 15 authorised directors of companies and juristic persons, faces a maximum punishment of life imprisonment and combined fines of 35 billion baht.