
The National Anti-Corruption Commission (NACC) found grounds to charge the duo for having the Cabinet endorse the joint communique that supports the listing of the ruins as a Unesco's world heritage site last year.
NACC's deliberation on the issue had cover 44 accused ministers and officials. All officials were found not guilty.
Under Article 190 of the Constitution, the government is obligated to seek approval from parliament on the framework to negotiate an international agreement when it has ramifications in regard to borders.
Based on the Constitution Court ruling last year, the government failed to comply with Article 190. Noppadon was then disqualified from the position.