Nuon Chea, 86, has acute bronchitis; Khieu Samphan, 81, has intestinal problems, according to court officials.
The tribunal has suspended hearings for the week, and it remains unclear whether any will be held next week.
An update on scheduled hearings is expected Wednesday, but court monitors say Nuon Chea’s hospitalization is a reminder for the need of a speedy trial.
Nuon Chea collapsed in his cell at the tribunal detention center outside Phnom Penh on Sunday, Son Arun, his lawyer, said.
The tribunal will hear health arguments for Ieng Sary, who is 87 and was the Khmer Rouge’s foreign minister, on March 21 and for Nuon Chea, who is 86 and was the regime’s chief ideologue, the following day.
On that day, Vietnamese-led forces and Cambodian fighters entered the capital, ousting the Khmer Rouge, which had been in power since April 15, 1975.
‘Lost Loves,’ a feature film by Chhay Bora that describes daily life under the Khmer Rouge, screened this weekend at the Palm Springs International Film Festival.
Those cases—003 and 004—are strongly opposed by Prime Minister Hun Sen and other senior government officials, because they would require five more indictments of former Khmer Rouge cadre.
The anniversary is a divisive day in Cambodia, with some celebrating the ouster of the brutal regime and others marking the beginning of a 10-year Vietnamese occupation.
“Red Wedding,” a documentary that explores forced marriage under the Khmer Rouge, has won an award from the International Documentary Film Festival of Amsterdam.
Those two names have been carefully guarded by the court, despite a widespread leak of prosecution documents to journalists and court monitors over the past few years.
The Cambodian side needs about $9.5 million to operate in 2013.