Deputy Agriculture Minister Thamanat Prompow defended Palang Pracharath Party (PPRP) MP Pareena Kraikupt against encroachment allegations on Wednesday, saying her family had lived on the disputed land prior to the enactment of land reforms.
Ms Pareena told an investigation committee her family had occupied the plots since 1946, while the Royal Forestry Department only handed them over to the Agricultural Land Reform Office (Alro) in 1993, said the minister, who comes from the same ruling party.
"I have ordered an urgent meeting of the committee. Legal experts are probing to find the truth," he said, adding the land previously belonged to Ms Pareena's father.
Meanwhile, tax evidence used by the MP to prove her land ownership may backfire if she is not the person who actually pays the tax, said an official.
The Ratchaburi representative said on Tuesday she has a document, called Por Bor Tor 5, which shows her family pays tax for use of 1,000 rai in Moo 6, tambon Rang Bua, Chom Bung district. Ms Pareena was defending herself against a petition lodged with the National Anti-Corruption Commission by Pheu Thai member Ruangkrai Leekitwattana, alleging her land may be reserved for landless farmers.
Parts of the local forest were declared a land-reform zone in 2011 but have yet to be allocated to landless farmers.
Authorities want Ms Pareena, who has built a poultry farm on the land, to clarify its boundaries and present the tax evidence.
"But if the taxpayer is not Ms Pareena and a probe finds the land is in reserve forests, she will face an encroachment charge," said Somchai Prempanitnukul, chief of Forest Management Bureau 10 in Ratchaburi.
The disputed land was also allegedly divided into plots of less than 500 rai, so as to evade a 2016 land-reform order to reclaim land from farmers who occupied over 500 rai.
This may cause trouble for Ms Pareena, who has informed the corruption watchdog she owns 76 plots in Ratchaburi. Some 58 plots, covering 1,706 rai, are being inspected by environment and agriculture officials, including Ms Pareena's 1,000-rai farm.
To determine if the politician has done anything wrong, officials also need to know the current status of the reserves and the land-reform zone.
"But first we must give her a chance to present land documents or other evidence," said Royal Forest Department chief Atthaphon Charoenchansa.
Deputy Democrat leader Nipit Intarasombat said the Por Bor Tor 5 may be a double-edged sword for Ms Pareena.
The document shows a person pays tax to local officials but does not demonstrate ownership.
"How can it be used to claim rights over state land?" Mr Nipit wrote on Facebook.