This handout photo taken on October 19, 2011 shows former Khmer Rouge leader ex-social affairs minister Ieng Thirith.

Phnom Penh -

A Cambodian war crimes suspect would have found it difficult to fake dementia to avoid trial, medical experts said on Friday.

Leng Thirith, the Khmer Rouge's former social affairs minister, is accused of war crimes, crimes against humanity and genocide.

The 80-year-old's fitness to stand trial was being re-assessed by the UN-backed war crimes court in Phnom Penh.

Court-appointed medical experts said they believe she suffers from dementia, possibly the progressive brain disease Alzheimer's, which would be hard to fake.

Specialist John Campbell told the court there was no indication she was putting on the condition.

“It would be very difficult to feign the change to her personal hygiene, namely urinary incontinence and also her indifference to it,” added his counterpart, Dr Seena Fazel.

Fazel said a person faking mental health problems would likely maintain a “consistent approach” to memory loss, unlike Ieng Thirith.

The court heard Thursday that Cambodian physician Chak Thida thought Ieng Thirith was mentally able but possibly in a state of pre-dementia.

The tribunal estimated that 1.7 million to 2.2 million people died during the 1975-79 Khmer Rouge regime.- Sapa-dpa