A court in Cambodia has sentenced a political analyst to 18 months in prison on the basis of a criminal complaint by Prime Minister Hun Sen that he had defamed him in a radio interview.

Judge Ky Rithy of the Phnom Penh Municipal Court ruled Thursday that there was sufficient evidence to find Kim Sok guilty of defamation and a charge of inciting chaos.

Kim Sok was arrested in February after giving an interview to U.S.-funded Radio Free Asia that Hun Sen felt implied his government was behind the killing last year of another political analyst and critic of the government, Kem Ley.

Rights groups accuse Hun Sen's government of using the courts to harass its critics and political opponents.