The chances of the results being known today are slim, ICTY spokesman Christian Chartier said.
Dutch pathologists began the autopsy in The Hague around 1530 hours on Sunday, with Serbian pathologists attending. Autopsies are usually completed in four to five hours, but toxicological tests take up to 24 hours.
Serbia and Montenegro's Minister for Human Rights, Rasim Ljajic, who is also in The Hague, expressed hope that Milosevic's body would be handed over to his family immediately after the autopsy, i.e. on Monday.
The former Yugoslav president, who had been on trial at the ICTY for genocide in Bosnia-Herzegovina and war crimes in Croatia and Kosovo committed in the 1990s wars, was found dead in his cell at the ICTY detention unit in the Hague district of Scheveningen on Saturday morning.