The judge also summoned Kong Korm, an ex-opposition Sam Rainsy Party acting president and a former top adviser to the court-dissolved Cambodia National Rescue Party (CNRP), to answer questions this month in relation to the charge.
Former CNRP president Sokha was arrested in early September 2017 and charged with treason for allegedly colluding with the US to overthrow the government.
After spending more than a year in a Tbong Khmum province prison on pre-trial detention, he was released on bail in September last year and resides at home under court-imposed conditions.
According to a court document released on Fresh News on Sunday, investigating Judge Ky Rithy on Friday rejected a defence letter seeking Sokha’s charge be dropped.
“In the process of the investigation, the investigating judge must collect enough evidence according to criminal procedures before deciding to close the investigation,” Judge Rithy ruled.
“The prosecutor has requested further investigation, including [testimony from] witnesses involved according to a [prosecution] letter . . . and so the investigating judge has summoned more witnesses for questioning soon,” he wrote, adding that the investigation was in the process of gathering further evidence.
“Therefore, a request dated Thursday, December 27, 2018 by the co-lawyers defending Kem Sokha is rejected,” Rithy concluded.
Chan Chen and Meng Sopheary, two of Sokha’s team of four defence lawyers, could not be reached for comment.
Pheng Heng, another Sokha co-lawyer, declined to comment on Sunday, but he told The Post last week that the defence team had requested that the charge be dropped as the accusation behind it was baseless.
“There is no factual base that can have him charged with treason. There were no foreigners who came to collude with him in order to topple the government,” Heng claimed.
He said he was not sure when the trial would open.
“[Sokha’s] release on bail by the court has restricted his freedom. The conditions he must follow are so strict, but [being granted bail allows him] out of detention in the prison,” he said.
“From his arrest [in September 2017] until now, it has been more than a year and we have requested that the charge be dropped a number of times already. This is the third time,” he said.
The investigating judge summoned Korm to appear in court on January 23 for questioning as a witness, said a court document dated December 26 that was released on Fresh News on Sunday.
“The person concerned has to appear in court . . . and bring along documents linked to the case if available,” the summons says.
Political analyst Lao Mong Hay said: “The court should summon all witnesses, including foreign ones, to get to the truth of the matter, and to ensure that Kem Sokha’s guilt, if any, is proven beyond any reasonable doubt.”
Ou Virak, another political analyst, could not be reached for comment by The Post regarding the case.
An investigating judge in February last year rejected Sokha’s request that he interview a representative from the US government in connection with the case despite Sokha being accused of plotting a US-backed overthrow of the Cambodian government.
The judge at the time reportedly claimed that a 2013 video in which Sokha tells a crowd of supporters in Australia that he received political advice from the US was sufficient evidence of the matter.
Sokha was arrested in a midnight raid in September, with the 2013 video serving as the only evidence of his purported treason.
Judge Rithy did not respond to questions from The Post, while Korm could not be reached for comment.