Cambodian People’s Party spokesman Chhim Phal Virun has been called as a witness in the controversial “treason” case against jailed opposition leader Kem Sokha.

Sokha, the leader of the now-dissolved Cambodia National Rescue Party, was arrested in September and taken to prison. The arrest was largely tied to a 2013 video in which he talked about receiving US advice.

Phal Virun was Sokha’s deputy at the Cambodian Center for Human Rights, but left the organisation – which Prime Minister Hun Sen recently threatened to close – in 2006 and accused Sokha of corruption and embezzling funds.

“I will appear to fulfil the law, under my obligation as a Cambodian citizen that respects the law,” Phal Virun said yesterday.

“I will speak only the truth and what I know, and [if questioned about] what I do not know, I will answer that I do not know.”

According to a document signed by Municipal Court Investigating Judge Ky Rithy, Phal Virun will appear as a witness on February 6 for “clarification” related to allegations of Sokha’s “collusion with foreigners”.