FIVE more rights groups have demanded that Born Samnang and Sok Sam Oeun - convicted of murdering outspoken union leader Chea Vichea - receive a fair and impartial hearing in front of the Supreme Court on Wednesday.
The pair have spent nearly five years in prison for a crime that many NGOs say they did not commit.
The Cambodian Confederation of Unions, the UN Office of the High Commissioner for Human Rights (UNOHCHR), Human Rights Watch, the International Trade Union Confederation and the Observatory for the Protection of Human Rights Defenders are the latest groups to call upon the Supreme Court to exonerate the two men.
The Cambodian Confederation of Unions, whose president, Rong Chhun, was a close friend of Chea Vichea, called their previous trials a "parody of justice".
The UNOHCHR said that if the Supreme Court sent the case back to the Court of Appeal, it would show the world Cambodia had begun "an effort to combat and curb impunity" in the judiciary.
The UNOHCHR pointed out that the first investigating judge dismissed the case and that the men were convicted primarily on the basis of a retracted confession.
Both were "reasons to doubt of the validity of the convictions", the agency said.