Another 415 rai was added to the total yesterday with the declaration of six plots that are now subject to a Phase III investigation.
The Department of Special Investigation is taking a slow but sure approach to the Phase I investigations involving 11 plots because two five-star resorts occupy some of the disputed land.
Mapping experts are now involved to make sure the accusations are precise, the Chief of the DSI's Consumer and Environment Protection Office, Colonel Prawuth Wongsinil, said yesterday.
''Protests have come from many fronts because of the investigation,'' he said. ''But we intend to proceed and fully establish the facts.''
The parkland detectives have made it plain that the present owner-occupiers of the disputed properties are not necessaily at fault because the trail of suspicious land title transfers extends back two decades.
Some of the present owners are unlikely to have been aware that they were being sold stolen parklands.
The Director of Sirinath National Park, Cheewapap Cheewatham, reckoned that up to 3000 rai of the park's 12,000 rai had been ''attacked by investors'' over the years.
The Phase II investigation consists of four plots, totalling 134 rai.
Over two days, officials from the Royal Forests Department have made raids on land with DSI officers in Phuket's Thalang district and at Sirinath National Park.
The officials are investigating felled trees that are wanted for use in the perfume industry.
Some of the felled timber was so close to the offices of National Park rangers that they must have been aware it was being cut, investigators said.
The irony is that the trees grown on Phuket are of poor quality for perfume and would probably be difficult to sell, according to Royal Forests officers.