Updated

The leader of Cambodia's now dissolved opposition party was released on bail Monday after being jailed for a year on a treason charge.

The Phnom Penh Municipal Court said in a statement that Kem Sokha was granted bail due to health reasons. It stressed that the case against him would proceed.

He was returned in the predawn hours to his Phnom Penh home, where hundreds of supporters gathered later in the morning.

The action was the latest in a series of releases of government critics that follow the landslide victory of Prime Hun Sen's Cambodian People's Party in a July general election.

Hun Sen, who has held power for more than three decades, has a history of cracking down hard on his foes when he is challenged, then easing up when the threat has passed.

Last year's crackdown came as his party looked vulnerable for this year's polls. Kem Sokha's opposition Cambodia National Rescue Party had made a strong performance in 2017's local elections, building on its surprisingly strong challenge in the 2013 general election.

Kem Sokha was arrested last September on the basis of years-old videos showing him at a seminar where he spoke about receiving advice from U.S. pro-democracy groups. His opposition Cambodia National Rescue Party denied the treason allegation, calling it politically motivated.

Another court last November dissolved the opposition party, saying it was plotting with U.S. assistance to overthrow the government of Prime Minister Hun Sen, who has led the country for decades. With no credible opposition, Hun Sen and his party won July elections to extend his stay in power, in a vote seen by much of the international community as unfair.

Sam Rainsy, the co-founder of the Cambodia National Rescue Party, said on his Facebook page that Kem Sokha's release was only a first step, and should be followed by more moves by Hun Sen to restore democratic politics to Cambodia.

In addition to Kem Sokha being arrested and the Cambodia National Rescue Party being dissolved, 118 senior party leaders had been barred from politics and more than 5,000 party members holding local elected posts were forced out of their jobs.

Sam Rainsy said those measures should be reversed, with the local officials restored to their jobs. He also demanded that the opposition party should be legalized again, and that new elections be held, monitored by the international community.

Sam Rainsy, Kem Sokha's predecessor as opposition leader, has been in self-imposed exile to avoid serving prison time on a criminal libel conviction that is widely seen as politically motivated.

"While's it's a step forward that he's out of detention, he should never have been arrested in the first place," said Phil Robertson, deputy director for Asia of New York-based Human Rights Watch. "There's been no justice served here, just the temporary release of an opposition political leader that prosecutors could undo at any time."

"Despite the excitement connected to today's release, we're still a long way from a meaningful restoration of democracy and respect for human rights in Cambodia," he said.

On Aug. 30, a court had extended Kem Sokha's pre-trial detention by six months, disappointing Kem Sokha's supporters. They had hoped he might be released because more than 20 people imprisoned for political activities had been freed with pardons or on bail.

A day earlier, Hun Sen said publicly that Kem Sokha would not be released and would not receive a pardon because he has not yet been convicted.