The Khmer Rouge tribunal’s Trial Chamber had no alternative but to declare former Khmer Rouge social action minister Ieng Thirith unfit to stand trial in the court’s second case and order her unconditional release from detention, the Chamber ruled yesterday.

“The accused would be unable to understand sufficiently the course of the proceedings to enable her to adequately instruct counsel and effectively participate in her own defence,” the decision reads.

The decision was issued one working day before opening statements in case 002 are set to commence.

Although the Trial Chamber agreed unanimously that proceedings against 79-year-old Ieng Thirith should be stayed and charges against her severed from case 002, it split down national and international lines on the conditions of her release and the likelihood of her condition improving.

The Chamber’s three national judges argued that Ieng Thirith should be hospitalised under the government’s security, among other conditions, pending a re-assessment of her condition after a six-month period.

The two international judges argued that Ieng Thirith’s condition was “unlikely to improve” and there was no legal basis for ordering her mandatory hospitalisation and treatment.

They also said the stay of proceedings against Ieng Thirith was “likely to be permanent”.

Without an agreement on the conditions of her release, the Trial Chamber ruled the only solution was unconditional release, pending a potential appeal from the prosecution.

Phat Pouv Seang, co-defence counsel for Ieng Thirith, said yesterday his client would remain at the ECCC detention facility for a short period of time pending that potential appeal.

“If the prosecutor[s] oppose the court decision and they file an appeal, then the court will have to send the case to Supreme Court Chamber,” he said. “If they found as the Trial Chamber did, then [Ieng Thirith] will be released.”

International co-prosecutor Andrew Cayley said he would consult with national co-prosecutor Chea Leang today regarding a potential appeal.

“The decision came in very late.  I haven’t had the opportunity to consult with my national colleague,” he said.

Ieng Thirith is one of four remaining senior leaders of the Democratic Kampuchea regime who was set to stand trial for crimes against humanity, genocide and grave breaches of the Geneva Convention.

Ieng Thirith’s mental health has long been the subject of speculation, with the defendant previously exhibiting unpredictable behaviour in court.

During a 2009 hearing, she declared that those who accused her of murder would be “cursed to the seventh level of hell”.

At a hearing in August, New Zealand geriatrician John Campbell testified that Ieng Thirith had an “underlying dementing illness”, mostly likely caused by Alzheimer’s, and would have “great difficulty” testifying in her own defence.

Two of four psychiatric experts appointed by the court to conduct further assessment of Ieng Thirith’s mental health testified at a hearing last month that she suffered from dementia – the most likely form of which was Alzheimer’s – and was likely to “interrupt” proceedings should she declared fit to stand trial.

Lawyers for Ieng Thirith have previously stated that they could not take instructions from their client, and said in a filing earlier this month that she would be unable to make a statement or testify in the trial’s opening stages.

Clair Duffy, a tribunal monitor for Open Society Justice Initiative, said yesterday she was “encouraged” that international legal principles had been applied to reach the conclusion of Ieng Thirith’s unconditional release.

“Because of the disagreement, really what prevailed was that [the Trial Chamber] decided to act most favourably to her, and that’s a basic international legal norm,” she said, adding that the court needed to properly educate the public, including victims and civil parties, about the decision.

Duffy said that if prosecutors appealed the decision within a 24-hour time period, the Supreme Court Chamber would have two days in which to decide whether to stay the order for Ieng Thirith’s release.

Court spokesman Lars Olsen said that if prosecutors did not file an appeal, Ieng Thirith would be “free to go whenever she likes”.

“She will receive no more medical treatment from the court, and her medical treatment will be up to her,” he said.

Tuol Sleng prison survivor Chum Mey, 80, said he was “not happy” with the decision and accused Ieng Thirith of feigning her mental-health problems.

“I’m afraid that other defendants will follow her, to pretend to be seriously sick and to be very fragile and say that they cannot join the trial,” he said.