Kittipat Tharapiban said he had alerted Phuket's governor, Maitree Intrusud, to the problem and suggested that there be no sign-offs on similar sales.
The deals, he said, had been negotiated using documents provided through the Thalang Land Office.
He named three Thais over a total of 250 rain that he said had been appropriated from the national park between the hulk of the partly constructed Peninsular and the Pullman Phuket Arcadia Naithon Beach resort.
Only two people had initially been awarded sor por kor titles to use the land inside the park for agricultural purposes, and the three people who claimed the 250 rai were not among them.
A constant source of issues down the years has been the misuse of sor por kor titles on Phuket, commonly known as ''flying'' sor por kor titles. They can be transferred to other plots of land and also grow in size.
Khun Kittipat told the media yesterday that he intended to file complaints at Thalang Police Station today against the three Thais who had claimed tracts of Sirinath - Nakorn Wongsrithong, Chan Pongpa and Anoma Fangsen.
Five former directors of the park are being sued for dereliction of duty and one former governor of Phuket is also being investigated.
Hundreds of rai along the park's outer edge are alleged to have been misappropriated.
''Big or small, all claims will be looked at,'' he told locals yesterday. ''I also accept that some staff from the park have been involved in this corruption.''
He added that 173 people were entitled to grow produce in the park. Their claims predated the declaration of Sirinath as public space on June 30, 1998.