The airport construction project on Koh Phangan by commuter carrier Kan Air has trespassed on Than Sadet-Koh Phangan National Park, Surat Thani deputy governor Ouaychai Innak said on Wednesday.
Mr Ouaychai said an inspection carried out by forestry officials found part of the land on a mountain in Thong Nai Pan bay which had been prepared for the planned airport construction had encroached on park land. The encroached areas covered about 20 rai.
He said authorities had filed a complaint with police.
Provincial authorities recently ordered Kan Air to suspend the construction of the first airport on the home of the famous full moon parties after receiving a complaint that the project may have encroached on the national park land.
Mr Ouaychai said three working panels have been set up to investigate the matter and officials were now examining the origin and issuance of Nor Sor 3 and Sor Kor 1 land documents given by the company.