Bali, Phnom Penh  - An appeal against his pre-trial detention by a Cambodian genocide court from former Khmer Rouge foreign minister Ieng Sary was adjourned Tuesday with legal arguments still raging.

Court officials said the case would resume Wednesday morning, but would not predict whether a verdict would be returned the same day.

Court hearings in the Cambodian judicial system rarely last more than a day, and some less than an hour, making the case being held by the international standard joint UN-Cambodian court set up to try former leaders almost unprecedented.

The 82-year-old is charged with war crimes and crimes against humanity for his alleged role in the 1975-79 Khmer Rouge regime during which up to 2 million Cambodians died.

Despite his reported frail health, Sary appeared in court for a second time, but did not speak as complex legal arguments continued throughout the day.

Sary's lawyer Ang Udom has argued that his client was too old and frail to be a flight risk or a risk to witnesses and appealed for his release on bail - a claim disputed by the prosecution.

Sary was pardoned by then-King Norodom Sihanouk of charges of genocide in 1996 but no mention was made of the charges that were eventually brought against him by the hybrid court, to which he has pleaded not guilty.

His wife Ieng Thirith as well as former head of state Khieu Samphan, movement leader Pol Pot's chief deputy Nuon Chea, and former chief of the Toul Sleng torture centre Kaing Guek Eav, alias Duch, are the other four former leaders in custody.

Similar appeals by other defendants of the court have already failed, but Sary argues that he has a serious heart condition and has received constant medical treatment since his arrest in November.

Hearings are expected to get underway later this year. (dpa)