Independent researcher Chan Vibol has been charged with plotting and incitement after participating in a May workshop run by the land rights group Coalition of Cambodian Farmers Community (CCFC), according to a Tuesday evening statement from the Ratanakiri provincial court.

Vibol, who is not a CCFC employee, is the fourth person to face charges for attending the multi-day workshop in Ratanakiri. The court has issued a warrant for Vibol’s arrest, according to court spokesperson Keo Pisoth, Ratanakiri court spokesperson.

After reviewing the evidence, the prosecutor described the workshop as a “secret gathering which discussed political issues to cause incitement in farmers to rise up and cause turmoil in society, leading to the overthrow of the government,” according to an unofficial translation of the court’s Tuesday statement.

“The investigating judge is further investigating their computers and some documents,” Pisoth said. But he declined to share further information about the specific evidence underpinning the court’s allegations.

The several dozen CCFC workshop attendees had their phones collected and put in a box of drinking water bottles, while a security camera was turned away to avoid recording the workshop’s activities, according to the court’s statement.

On Monday, the court brought the same charges of plotting and incitement against CCFC president Theng Savoeun and two colleagues, who have been in custody since May 17 and were placed in pretrial detention earlier this week.

Last week, Interior Ministry spokesperson Khieu Sopheak accused workshop participants of plotting a “peasant revolution” which CCFC representatives and supporters have repeatedly denied.

The charges for the four detained workshop participants are under articles 453, 494 and 495 of Cambodia’s criminal code. Plotting carries a five to 10 year prison sentence and a 4 million riel fine — approximately $972.

Senior investigator for human rights group Adhoc, Soeng Sankaruna, said he was disturbed by the court’s characterization of CCFC’s workshop as a “secret” gathering as opposed to a routine internal discussion.

“It is very concerning because usually civil society groups have cooperated together in monitoring and training citizens on their rights,” he said. “In general meetings, they don’t want to reveal what they are discussing to the public and I believe other institutions who have a meeting also don’t want everybody to know about their meetings too.”

“It will make other civil society groups concerned about organizing assemblies as any accusation might happen,” he added.

Vibol earned a PhD in political science from the Royal Academy of Cambodia in 2013.

As a freelance researcher, Vibol has produced reports that include surveying the Kingdom’s NGO operations and providing recommendations for improving civil society work in the Kingdom.

Vibol could not be reached for comment.

Vibol wrote on his Linkedin that he is “envisioning to see all live in peace and dignity.”