Persecution of opposition media remains an obstacle to free and fair elections, an election monitor said Thursday.

"Closure or prohibition of any media has an impact on free and fair elections," said Mar Sophal, an investigator with the independent Committee for Free and Fair Elections, as a guest on "Hello VOA."

Opposition editor Dam Sith was arrested earlier this month, facing a suit of defamation and disinformation. He was released last week, but his arrest and the recent closure of a provincial radio station have prompted worries over media freedom ahead of the election.

Government spokesman Khieu Kanharith said Dam Sith's arrest was an affair of the court and not related to the government.

Meanwhile, 40 media outlets nationwide support the ruling Cambodian People's Party, Mar Sophal said, adding that people in the provinces were not getting enough news about the impending election.