Defense for the aging Khmer Rouge social affairs minister say they want her excused from trial at the UN-backed tribunal.

Now 69, she suffers from knee problems, poor eyesight and insomnia, according to her lawyers.

The court will determine whether or not she is fit to stand trial, a tribunal spokesman said. However, a source close to the case said it was possible she would be excused from the proceedings.

The old age of four defendants on trial for atrocity crimes is a major challenge for the court. Under the rules of the tribunal, the defendants are to be medically evaluated before standing trial.

“We requested her release on bail during provisional detention because of her health, and in the next step of the trial we jumped another step,” said Phat Pouv Seang, a defense lawyer for Ieng Thirith.

Lars Olsen, a spokesman for the tribunal, said “some of the defendants” in Case 002, which wrapped up a preliminary hearing last week, will have their health assessed.

“That evaluation will soon be completed, and if anyone is to be excused from the trial proceedings for medical reasons, this will be made public,” he said.

Ieng Thirith is charged with war crimes, crimes against humanity, genocide and other crimes, alongside her husband, Ieng Sary, the former foreign minister of the regime; Nuon Chea, its chief ideologue; and Khieu Samphan, the nominal head of the movement.

Clair Duffy, a court monitor for the Open Society Justice Initiative, said all except Khieu Samphan were having “extensive” medical checks ahead of a trial, which is slated to begin later this year.