A group of Southeast Asian lawmakers are calling for the “immediate and unconditional release” of Cambodian opposition leader Kem Sokha on the cusp of the six-month anniversary of his arrest.

Sokha, former president of the now-dissolved Cambodia National Rescue Party, was arrested on September 4 and charged with “treason” over remarks he made during a 2013 speech in Australia about receiving career advice and assistance about democratic change from the US.

Charles Santiago, spokesman for the Asean Parliamentarians for Human Rights, today said Sokha’s continued detention was “an outrageous abuse of power by Cambodia’s ruling party”.

“The charges are so blatantly politically motivated and the judiciary so clearly acting at the behest of the Prime Minister that it’s a wonder the government even bothers going through the motions,” he said.

“These trumped-up charges should never have been brought in the first place. They should be immediately dropped and Kem Sokha unconditionally freed.”

Cambodia’s Ministry of Foreign Affairs today defended all legal measures taken in cracking down on what they have termed a “colour revolution”, even as the United States cut off aid to the Kingdom this week over its recent actions. Sokha's party was forced to dissolve at the government's request in November.