An NACC source said on Monday that the agency had asked the Natural Resources and Environment Ministry and the Office of Attorney-General to take disciplinary and criminal action against Chaiwat and a few accomplices since late last month.
The source said the NACC had grounds to suspect that Chaiwat and a few other officials at the National Kaeng Krachan Park were guilty of graft related to the construction of an office in the Huay Komrit area within the park.
The source said the alleged crime took place when Chaiwat was chief of the park several years ago.
After an extended investigation, the NACC concluded that Chaiwat had abused his authority as park chief to distort information on an official document to help a private firm win the project without undergoing the normal bidding process, the source said.
Chaiwat is accused of violating Articles 157 and 162 of the Criminal Code on negligence of duty, violating Articles 4 and 12 of the State Agency Procurement Act and Article 172 of the NACC Act.
Chaiwat and his alleged accomplices were also accused of allegedly committing severe disciplinary offences by violating Article 85 of the Civil Service Act, the source said.
The alleged accomplices have been identified as Suporn Polphan and Duangphet Santhong, both Kaeng Krachan park officials.
The source said the NACC also found another official, Nijitnapong Banthitsamit, to have committed disciplinary offences, but did not take part in the alleged corruption.