The trial of Sam Rainsy Party Senator Hong Sok Hour over a Facebook post deemed treasonous by Prime Minister Hun Sen began yesterday at Phnom Penh Municipal Court, after another bail application for the lawmaker was rejected.

As some 50 opposition supporters protested outside, Sok Hour, clad in orange prison garb, listened as presiding judge Ros Piseth detailed the three charges in the case, which rights groups have slammed as politically motivated.

According to Piseth, Sok Hour allegedly forged a public document, used a forged public document and incited social unrest, charges that carry a potential combined sentence of 17 years in prison.

The charges stem from a fake version of a 1979 border treaty between Cambodia and Vietnam in a video posted to Cambodia National Rescue Party president Sam Rainsy’s Facebook page on August 12.

In the video, played to the court, Sok Hour highlights Article 4 of the treaty, purporting to show Heng Samrin, then head of state, agreeing to dissolve the country’s national borders. However, Piseth said that was “totally opposite” to the real article, which states the two countries would respect the border line and solve disputes peacefully.

Noting the post was shared across Facebook and other social media, Piseth said Sok Hour had “broken Cambodia’s laws”. He said the post aimed to incite serious unrest, which threatened social security, stability and public order.

Yesterday, the senator, a dual Cambodian-French citizen, admitted filming and posting the clip, further saying he chose to use Rainsy’s Facebook page because it had more followers.

However, he denied creating the treaty and said he was unaware it was fake, saying he downloaded it through a Google search between 2006 and 2007. He explained his “main purpose” was to share information about the Vietnam border issue.

“I did not write or fake or redraw the document. I just cut it and inserted it into the video clip … the documents were forged already, but I did not know that they were fake because I did not find the original. If I had [the original] I would have posted it on Facebook.”

Sok Hour declined to answer questions about his assistants who helped post the video, three of whom have fled the country and are applying for asylum in the West, the Post revealed last month.

He also accused prison staff of political discrimination for refusing to let him see an outside doctor for high blood pressure and other medical conditions.

Sok Hour’s lawyer, Choung Choungy, added that no witnesses had testified that Sok Hour had produced the fake document and rejected the charge of incitement.

The case is seen by the opposition and rights groups as a part of a political crackdown by the government against the CNRP’s politicking on the Vietnam border, including allegations the government was complicit in allowing territorial encroachment.

Sok Hour was detained by military police on August 15 despite his senatorial immunity just days after Prime Minister Hun Sen called for his arrest, labelling the post treasonous. The trial resumes on Wednesday.