An appeals court in Cambodia has for the second time denied a request for the release on bail of opposition leader Kem Sokha, who has been charged with treason.

The Thursday court appearance in Phnom Penh by Kem Sokha, head of the Cambodia National Rescue Party, was his first since his arrest last September. His hearing was held behind closed doors and journalists and other onlookers were kept away.

His prosecution by the government of Prime Minister Hun Sen is widely seen as part of a concerted effort to cripple the opposition ahead of a general election this year.

Kem Sokha's lawyer, Choung Choungy, says the court cited concerns for his client's security in denying bail.

The government has expressed fears of political protests by Kem Sokha's supporters.