The health of former Khmer Rouge minister of social affairs and former war crimes tribunal defendant Ieng Thirith has deteriorated to the point that she requires oxygen and a feeding tube just to stay alive, her son said on Wednesday.

Thirith, 82, has been hospitalised in Thailand since March. Rather than improving, her condition actually seems to be worsening, raising doubts as to whether she will ever return, according to her son Ieng Vuth, the deputy governor of Pailin province.

“Her condition is bad, and [her health] is not coming back. The doctors claim it’s difficult to treat her due to her old age,” Vuth said.

“I don’t know what to do now; [I can] only keep her in treatment there. She cannot eat or drink.… She is in bad condition now, because she can only rely on the [feeding] tube and oxygen.”

Thirith has remained under judicial supervision since her provisional release in September 2012, when the court ruled that her advancing dementia rendered her unfit to stand trial. Proceedings against her husband, ex-Khmer Rouge minister of foreign affairs Ieng Sary, were terminated in March last year, when the 87-year-old died of heart failure in Phnom Penh after two weeks in hospital.

Sary and Thirith were two of a handful of senior leaders who served under Pol Pot at the helm of the Democratic Kampuchea regime, which came to power in the mid-1970s and introduced an agriculturally driven revolution that killed upwards of 1.7 million people.

The married couple and two other senior officials were arrested and brought to trial for Case 002 to face charges of crimes against humanity and genocide, among others.

The Khmer Rouge tribunal is expected to deliver a verdict in the first phase