
Sarawut Menasawet said this when he testified before a House of Representatives committee on agencies set up under the Constitution, state enterprises and public organisations.
Sarawut said the nine NCCC members were appointed under orders by the coup-makers after they seized power in 2006.
The official said he consulted the Cabinet secretariat about seeking royal endorsement for their appointment.
And he was told the National Security Council, the junta at the time, was considered to hold sovereign power and thus their orders were lawful.
The NCCC secretary-general, who is a permanent official, also explained an accusation that the agency was derelict in its duty for failing to look into alleged shareholdings of opposition MPs and senators.
He said the NCCC had no duty to investigate whether any senator or MP held shares contrary to the law.
"The NCCC duty is to find out if any MP or senator conceals his or her assets, and if they are unusually wealthy," he said.