Deflecting allegations that Milosevic was poisoned or that he had unknowingly ingested a drug that countered his heart medication, the president of the tribunal, Fausto Pocar, also told a packed news conference that no traces of the drug rifampicin were found in forensic tests.
However, Judge Pocar and the prison's overseer, Hans Holthuis, were grilled about how rifampicin, a powerful antibiotic that is known to counter the effects of heart medication, came to be found in Milosevic's blood in recent months, and how tribunal authorities reacted when they learned of it.
Milosevic died suddenly of a heart attack while nearing the end of his trial for war crimes including genocide during the Balkan wars of the 1990s.
Supporters allege he was poisoned but others allege he took un-prescribed medication on his own.
In Belgrade one of Milosevic's legal advisors, Branko Rakic, said the tribunal was "panicking and trying to whitewash" the fact that they denied Milosevic the treatment he needed.
"We cannot say he was murdered but certain omissions have been made and as a result, he died," Mr Rakic said.
Milosevic had asked in December to be sent to Moscow for medical treatment however the tribunal denied the request saying it feared the former Yugoslav strongman would not return from Russia where his wife and son also reside.
Prosecutors at the International Criminal Tribunal for the Former Yugoslavia (ICTY) voiced suspicions after Milosevic died that he was secretly using rifampicin in the hope of becoming ill enough to be accorded a medical evacuation to Russia.
The toxicological tests were conducted by the Netherlands Forensic Institute (NFI), which performed the autopsy, identifying the immediate cause of death as a heart attack.
The public prosecutor's statement said that the NFI had informed it "that rifampicin disappears from the body quickly and the fact that no traces were found implies only that it is not likely that the rifampicin had been ingested or administered in the last few days before death."
Funeral preparations
Meanwhile preparations are underway for Milosevic’s burial to be held in the grounds of his home in Pozarevac, east of Belgrade.
Thousands of mourners have already paid their final respects after the body was laid out in the communist-era Revolution Museum of suburban Belgrade.
Russian Communist Party boss Gennady Zyuganov, one of the few foreigners set to attend the funeral, said as he arrived that Milosevic's widow, Mira Markovic, may not come as Serbian authorities had not guaranteed that she would not be arrested.
"It is enough that Marko has lost his father, he should not lose his mother as well," he told reporters, referring to the couple's son who also has yet to arrive. Both are believed to have been living in Russia for years.
A Belgrade court has revoked an arrest warrant for Mrs Markovic but ordered her to surrender her passport and report to a court on March 23.