Despite travelling to Thailand this month to receive medical treatment for a host of ailments, former Khmer Rouge tribunal defendant Ieng Thirith’s condition is worsening, and she is likely to remain hospitalised there for some time, her son said yesterday.

According to Ieng Vuth, the deputy governor of Pailin province and Thirith’s son, the former Khmer Rouge minister of social affairs suffered a broken hip in a fall from her bed, a condition that isn’t healing, because pain caused by a heart condition prevents the 82-year-old from lying still.

“Her health has not improved; instead it is worsening.” Vuth said. “And we do not know how long she will stay in the hospital.”

Though Thirith remains under judicial supervision, she was released from detention and court proceedings against her were stayed in September 2012 after she was found unfit to stand trial due to advancing dementia. The dementia, Vuth said yesterday, makes it more difficult for doctors to treat her, and more difficult for Thirith to understand their instructions.

“Of course, we are really concerned about her condition,” he said, adding that the family was closely monitoring the situation.

A filing in which Thirith requested permission to travel to Thailand notes that in addition to conditions affecting both the spine and the artery that carries blood to the lower body, Thirith showed “evidence of cerebral atrophy” as well as two small strokes in a CT scan in January.

Thirith’s treatment in Thailand coincides with the court’s reassessment of the fitness to stand trial of its remaining defendants – 82-year-old ex-head of state Khieu Samphan and 87-year-old Brother No 2, Nuon Chea.

The two underwent a physical and psychological assessment on Tuesday, but an optional public hearing on the findings that had been tentatively scheduled for Friday wasn’t held because none of the legal teams requested it.

“The medical reports are confidential, however the two reports indicate that both accused are fit to stand trial,” said prosecutor William Smith in an email yesterday. “There is no information in the reports that presents any immediate concern as to their health in the foreseeable future.”

ADDITIONAL REPORTING BY STUART WHITE