The National Anti-Corruption Commission (NACC) has issued summons notices for six people, including former commerce minister Boonsong Teriyapirom and his then deputy Poom Sarapol, after they failed to turn up to acknowledge malfeasance charges in the government's rice sale last month.
The other four accused officials are Ratthanit Sojirakul, Somkid Euansupha and Lit Phojai, representatives of the private firms, and Manas Soiploy, director-general of the Department of Foreign Trade.
The group was accused by the anti-graft agency of malfeasance in the sale of paddy rice under the government-to-government (G-to-G) deal.
Mr Ratthanit, Mr Somkid, Mr Lit, Mr Manas and Mr Poom were summoned to the office to acknowledge the charge on Feb 11, while Mr Boonsong was asked to hear it on Feb 21. All failed to show up at the NACC office.
The summons will be shown at the NACC offices in Chiang Mai for Mr Boonsong, Khon Kaen for Mr Poom and Phrae for Mr Lit.
The summons of the rest will be displayed at the NACC office on Sanambin Nam Road in Nonthaburi.
The anti-graft agency on Feb 18 also charged caretaker Prime Minister Yingluck Shinawatra with dereliction of duty over alleged irregularities in the rice-pledging scheme.
Ms Yingluck failed to meet the NACC to acknowledge the matter late last month.
The premier's lawyer asked the NACC on March 12 to delay submitting her defence for the case by 45 days, but the agency gave Ms Yingluck 15 more days to present it.
If the NACC indicts her, she will have to leave office.
Speaking about the effort carried out by Ms Yingluck's lawyers to file the impeachment motion against NACC commissioner Vicha Mahakhun, NACC secretary-general Sansern Poljiak said Mr Vicha was undeterred and disregarded the move.
The NACC vowed to adhere to the laws and evidence concerning every case, he said.
Mr Sansern also shrugged off concerns over the red shirts' threat to lay siege on the NACC office if it rules to indict the premier.
He said people should adhere to the laws.