PHNOM PENH, Cambodia — A Cambodian court on Monday sentenced an opposition senator to seven years in prison over comments he posted on Facebook criticizing a 36-year-old border agreement with neighboring Vietnam.
Judge Ros Piseth of the Phnom Penh Municipal Court found Senator Hong Sok Hour, a member of country’s main opposition Cambodia National Rescue Party, guilty of falsifying public documents, using fake documents, and inciting chaos.
Hong Sok Hour and his defense lawyer did not appear before the court, but Son Chhay, an opposition lawmaker who attended the hearing, told reporters that the conviction reflected the court’s lack of independence.
‘‘For me, I am already aware that this case is political motivated,’’ Son Chhay said.
Hong Sok Hour was arrested in August 2015 after Prime Minister Hun Sen accused him of treason for the online posting, which included the purported text of a 1979 treaty with Vietnam that declared that their mutual border would be dissolved.
Hun Sen — who was foreign minister at the time in a government installed by a Vietnamese occupation force that invaded Cambodia to oust the murderous Khmer Rouge regime — insisted the treaty was forged.
Hong Sok Hour is the latest opposition figure to run afoul of the law in what activists say is the willful use of the courts to suppress government critics.
The case is one of several hanging over opposition leaders in what is generally seen as an attempt to disrupt their organizing efforts ahead of local elections next June.
The next general election is not until the middle of 2018, but holding power at the local level is an advantage when national polls are held.
On Friday, an appeals court upheld a five-month prison term for opposition leader Kem Sokha’s refusal to twice answer a court summons, in a case involving his alleged mistress, but which his supporters say is politically motivated.
A month ago, another opposition lawmaker, Um Sam Ann, who has been a strong critic of the government’s handling of demarcating the border with Vietnam, was sentenced to 2½ years in prison for his online postings.