Land surveys have so far confirmed that developers have encroached on 1,035 rai of Sirinat National Park in Phuket, park chief Kittiphat Taraphil said on Friday.
A total of 815 land plots covering 4,346 rai had been examined so far, Mr Kittiphat said.
Clear encroachment had been found in 1,035 rai. The remainder of the encroachment claims were still under investigation.
The department had informed the Lands Department to revoke the ownership of 16 areas of land covering 244 rai and it had referred cases involving 48 other sections to the Department of Special Investigation.
He said the park faced difficulties in its attempt to reclaim forest land from encroachers, with no progress in litigation cases.
Mr Kittiphat suggested the government apply Section 44 of the interim constitution to speed up legal procedures against land encroachers.
Samak Donnapee, director of the National Parks Office, said the issuing of land title rights in the park was illegal. Most of the land was claimed using Sor Kor 1 documents which had been revoked and document holders already received the compensation.
Only two blocks of land had refused compensation and been granted a land title document.
He urged related agencies, especially the Office of the National Anti-Corruption Commission, to investigate the cases and punish offenders.
