Lawers for former Khmer Rouge foreign minister Ieng Sary have requested that Cambodia’s war crimes tribunal limit hearings in their client’s upcoming case to half-day sessions due to the 85-year-old’s fragile health.

In a filing dated Wednesday, the defence said Ieng Sary’s “age and ill health” would make full-day sessions unacceptably arduous.

“The defence team has been unable to meet with Mr Ieng Sary for more than approximately an hour at a time, and not more than two hours a day, because he has difficult sitting for longer and finds the intense concentration required to be quite draining,” the lawyers wrote, adding that their client’s urological problems necessitate frequent bathroom breaks.

Ieng Sary is set to be tried within the next six months for a raft of offences including genocide and crimes against humanity along with three elderly co-defendants: 79-year-old former Khmer Rouge head of state Khieu Samphan, 84-year-old Brother Number 2 Nuon Chea, and 78-year-old social action minister Ieng Thirith. A start date has not yet been set for the trial.

United Nations court spokesman Lars Olsen said yesterday that the defendants “have health conditions normal for people of their age, and they get regular medical check-ups”.

During a courtroom appearance in February to appeal his pre-trial detention, the court adjourned several times over the course of its morning session for Ieng Sary, who appeared with the aid of a cane and a back brace, to take breaks. He declined to speak at length during the hearing, delegating that task to his attorneys.

His wife, Ieng Thirith, may also be feeling the effects of her advanced age and has been given to unpredictable behaviour in the courtroom. In a 2009 hearing, she warned that those who accused her of murder would be “cursed to the seventh level of hell”.

In the court’s first trial – that of former Tuol Sleng prison chief Kaing Guek Eav – the court typically operated at most four days a week from 9am to noon and from 1:30pm to 4:00pm.