Officials from the Norodom Ranariddh Party on Wednesday called on the government to speed up its investigation into the alleged murder of a provincial activist.
Lun On, 41, was allegedly beaten to death by security personnel at a rubber plantation in Kampong Cham on the night of Dec. 30.
Human rights officials said he was killed for stealing rubber from the plantation, but NRP officials say he was taking rubber tree bark for cooking only.
There have been no arrests in the case so far.
Kompong Cham Police Chief Seng Sokim told VOA Khmer police had sent a report to the provincial court, and a decision was expected from the court.
"We have finished putting the case together," he said. "The case is under investigation."
Than Kim Hor, NRP acting secretary-general, said he did not believe the police had started an investigation.
"Even though the court has not indicted anyone, the police have the right to arrest and detain a suspect for up to 48 hours because a man died in this case," he said. "So this is a criminal case."
This was not the first time police failed to investigate the assault of an NRP activist, he said.
In March, a party activist was injured by a Cambodian People's Party district chief, and no one has been arrested so far, he said.