The Supreme Court yesterday ordered the provisional release of Thach Saveth, who was convicted in 2005 of killing a prominent trade unionist in a case rights groups have long charged was a set-up.

Judges instructed the Appeal Court to reinvestigate the case and ordered Thach Saveth, who had received a 15- year prison term, to be released following a formal request from the court for the Ministry of Interior’s approval. Thach Saveth did not appear in court yesterday.

Presiding Judge Khim Ponn said procedural irregularities in the case warranted the release of Thach Saveth, who formerly served as a paratrooper in the Royal Cambodian Armed Forces.

“There is evidence both to sustain and to reduce the charges, but four witnesses against [Thach Saveth] did not swear to their testimony” as they are required to do by law, Khim Ponn told the court.

“This is a criminal case which requires continued investigation, so the Supreme Court decides to release him on bail, but he must present himself following a request from the court.”

Thach Saveth was convicted of the murder of Ros Sovannareth, a Free Trade Union representative at the Trinunggal Komara garment factory in Phnom Penh who was shot in Tuol Kork district in 2004 while riding his motorbike. The verdict was upheld by the Appeal Court in 2009.

Ros Sovannareth’s murder came less than four months after the assassination of FTU president Chea Vichea, who was shot and killed outside Wat Langka in Chamkarmon district.

Thach Saveth has claimed he was travelling to Anlong Veng district in Oddar Meanchey province at the time of Ros Sovannareth’s murder and thus could not possibly have committed the crime. The case has drawn comparisons to that of Born Samnang and Sok Sam Oeun, two men who were convicted under dubious circumstances for the murder of Chea Vichea before being released pending a new investigation in 2009, having served nearly five years in prison.

Critics including current FTU head Chea Mony, the brother of Chea Vichea, have repeatedly called for the cases to be investigated properly and have suggested that government officials themselves may have been involved in the killings.

Speaking through tears outside the court, Thach Saveth’s mother, 49-year-old Huon Phalla, called her son “a good citizen who never committed such a crime”. Sam Chamroeun, Thach Saveth’s lawyer, welcomed his client’s release but said the court should drop all charges in the case.

In a statement released yesterday, the Cambodian Centre for Human Rights welcomed Thach Saveth’s release but said his original conviction raised questions “about the competence of the Cambodian judiciary and its failure to provide accountability in cases involving violent crimes against union activists, journalists and other human rights defenders”.