A resolution approving the inquiry was passed at today's meeting of the NACC.
The other four are former commerce ministers Niwattumrong Boonsongpaisan and Boonsong Teriyapirom, and former deputy commerce ministers Yanyong Phuangrach and Phum Sarapol.
Narong Ratha-amarit, an NACC member, was appointed to head the sub-committee to scrutinise the assets and liabilities of the five politicians to find out if they had accumulated unusual wealth from their handling of the rice-pledging scheme.
The subcommittee would coordinate with a subcommittee already investigating corruption in connection with the rice scheme, Mr Vorarit said.
Since the former members of the Yingluck administration left their ministerial posts in two groups, on May 7 and May 22, they were required to declare their assets and liabilities to the NACC by June 5 and June 20 respectively.
The declared assets and liabilities were expected to be revealed to the public early next month, Mr Voravit said.