The Central Criminal Court for Corruption and Misconduct Cases has issued arrest warrants for former Kaeng Krachan National Park chief Chaiwat Limlikit-aksorn and three others, on suspicion they murdered Karen rights activist Porlajee "Billy" Rakchongcharoen, who went missing in April 2014.
The fresh legal action against the group came on Monday as Mr Chaiwat, now the chief of Ubon Ratchathani-based Protected Area Regional Office 9, was assigned to work in Kanchanaburi.
"I'll meet the DSI today," confirmed Mr Chaiwat, referring to the Department of Special Investigation, which asked the court to approve its request for warrants on a total of eight charges yesterday.
Mr Chaiwat has long been the prime suspect in the case.
Porlajee disappeared in 2014 while he was helping his relatives sue Mr Chaiwat for setting fire to their bamboo huts and rice barns during a series of forest evictions.
Two other suspects who work for state agencies -- Bunthaen Butsarakham and Thanaset Chaemthet -- also face eight charges brought by the DSI.
Besides premeditated murder, the three are accused of detaining, robbing, and threatening the victim with weapons, and concealing his dead body.
The other suspect, identified as Kritsanaphong Chitthet, is not a state official and is accused of supporting the trio's alleged crimes.
Porlajee was last seen alive on April 17, 2014, after Mr Chaiwat and his officials arrested the Karen activist for allegedly collecting honey in the forest.
Mr Chaiwat and park officials were earlier charged over the disappearance but then acquitted for lack of evidence.
After reopening the case in June, the DSI discovered skull fragments in Kaeng Krachan reservoir that matched with the DNA of Porlajee's mother, and a murder probe was launched.
Mr Chaiwat disputed the DSI's assumption, saying the DNA match did not prove the bones belonged to Porlajee.
The DSI is now working with experts to analyse 30 more bone fragments, as well as questioning over 100 witnesses.
"What I can say at this moment is we can extract more genetic material from eight bones than from the skull," Central Institute of Forensic Science chief Pol Lt Col Wannaphong Khotcharak said yesterday.
To aid the DSI's investigation, the Public Sector Anti-Corruption Commission has handed over its findings from a separate probe into the case against Mr Chaiwat.
Porlajee's wife, Pinnapa Prueksapan, said she wants all the suspects to confess and take responsibility for what they did.
"If they dared commit this crime, they should have the courage to admit it," she said.
Billy: Vanished five years ago
Ms Pinnapa was speaking as she lodged a petition with the Justice Ministry, asking Minister Somsak Thepsutin to allow deputy DSI chief Korrawat Panprapakorn to continue his investigation into Porlajee's murder.
The cabinet last month approved a proposal to transfer Pol Lt Col Korrawat from the DSI to the post of inspector-general at the Justice Ministry. The DSI chief has since said the transfer stemmed from his own decision.
"I congratulate Pol Lt Col Korrawat for his promotion, but villagers want him to carry on with the job until it is completed," Ms Pinnapa said.
Mr Somsak said Pol Lt Col Korrawat will remain in his old post until his transfer receives royal endorsement.
"I believe he will finish the probe within three months as promised," Mr Somsak said.
