Following his detention this week, former Khmer Rouge foreign minister Ieng Sary was taken to the hospital for a checkup without his counsel present, lawyer Ang Udom said Wednesday.

This was "very surprising," he said, noting that standard practice should allow family members and counsel present for hospital visits.

"I dare not say it's legally wrong…but I personally wonder why I didn't I know," he said.

Ieng Sary, the former foreign minister of the Khmer Rouge, was taken for a medical checkup on Tuesday, following his arrest, along with wife Ieng Thirith, on Monday. He has been charged with crimes against humanity and war crimes, and the tribunal said Wednesday he would not be released ahead of his trial.

Ang Udom has said his health could deteriorate while he is in custody.

Medical checkups are viewed with some skepticism in Cambodia, following the death of Khmer Rouge commander Ta Mok in a Phnom Penh hospital last year.

Ang Udom said he was not given a clear answer from the tribunal on his exclusion from the checkup.