By NICHOLAS WOOD
BELGRADE, Serbia, March 13 — The Serbian government offered to allow the funeral and burial of Slobodan Milosevic to take place in Belgrade, paving the way for a gathering of nationalists and supporters of the former president that has not been seen in more than five years.
Government officials said a warrant for the arrest of Mr. Milosevic's wife, Mirjana Markovic, would be removed, enabling her and her family to attend what the one senior government official insisted would be a private ceremony.
Ms. Markovic had been wanted by a court in Belgrade after she failed to appear at a hearing to face fraud charges last year. The underlying charge, of fraud related to an apartment sale, still hangs over her, in theory. She is believed to have been living in Moscow for the last three years, during much of the time when her husband stood trial in The Hague on charges of committing war crimes in Bosnia, Croatia and Kosovo in the 1990's.
Mr. Milosevic, the former Yugoslav president, was found dead in his cell on Saturday, months before the case would have ended. He was 64.
An autopsy showed that a heart attack killed him, the United Nations war crimes tribunal said in The Hague on Sunday. The result was disclosed as new evidence emerged that Mr. Milosevic had been taking medicine not prescribed by his physicians, including an antibiotic known to diminish or blunt the effect of the medicines he had been taking for heart and blood-pressure problems.
The timing of the funeral was not announced. Despite the government's wishes for a quiet private ceremony, nationalists and supporters of the former president are certain to seize on it as a chance to rally.
Members of Mr. Milosevic's Socialist Party appeared to be seizing the opportunity to revive its flagging poll ratings and plan a mass gathering of supporters. The party was once the largest in Serbia, and now one that commands just over 5 percent of the vote.
Serbia's ultra-nationalist Radical Party, currently the most popular political party in Serbia, was also expected to ask its supporters to attend, party officials said. "I believe that first he has to be placed somewhere so people have a couple of days to express their respects, and then a large funeral," said Vladimir Krsljanin, a former foreign relations adviser to Mr. Milosevic.
"There will be foreign delegations and speeches and so on," Mr. Krsljanin said. He added the government needed to provide for the kind of ceremony the former president deserved.
"Such a large gathering of people and emotions can turn into something else, if the government doesn't show maturity," he said. "You cannot act against the masses."
Preparing the way, Deputy Prime Minister Mirosljub Labus told regional news stations that the government had informed the Milosevic family that it would allow the family to attend "a private funeral."
According to the independent news agency Beta, an assistant prosecutor in Belgrade, Mira Ilic, said the state prosecution service had asked that a detention order for Ms. Markovic be annulled by the county court. The court was expected to take its decision on Tuesday morning.
She is believed to have been living in Moscow for the past three years, with her son. At the same time, pressure grew among Mr. Milosevic's supporters abroad for a further investigation into his death and more specifically the discovery of a drug normally prescribed for tuberculosis in his blood. Russia's foreign minister, Sergey V. Lavrov, said he had prepared a team of doctors to take part in the investigation under way by The Hague tribunal.
Russia had offered guarantees that if Mr. Milosevic could travel to Russia for treatment, he would later return to The Hague, Mr. Lavrov said.
"In essence, they did not trust Russia," he said. "This cannot help but disturb us. And it cannot help but alarm us that Slobodan Milosevic died shortly after that.
"Since they did not believe us, we also have the right not to believe and not to trust those performing the post-mortem examinations," he said. "We have requested that the tribunal allow our doctors to take part in the examination, or at the very least to peruse the results."
The Russians and Serbs have long had close relations, and much of the Milosevic family has worked or taken refuge in Moscow. The Russian general, Leonid G. Ivashov, who visited Milosevic in prison in The Hague and testified on his behalf, said in Moscow: "I suspect that one of the reasons the tribunal did not allow his trip to Russia was because in Moscow, they would discover what drugs he had been given by the prison doctors, and they were afraid of being exposed."
In Belgrade, Mr. Milosevic's supporters appeared already to have come to a similar conclusion that their former leader had been murdered. Outside the headquarters of the Socialist Party in Belgrade, party members queuing in the rain to sign a book of condolence messages had no doubts he had been deliberately poisoned.
"They slipped it into his food," said Gjorgje Stejic, a 51-year-old machine engineer. "I am sure he was killed. That's what all of us think."
A 74-year-old retired high school teacher, Kolja Tanakovic, said, "They didn't have the evidence to convict him and so they murdered him."
Carla Del Ponte, the chief prosecutor at the tribunal, said at a news conference on Sunday before the autopsy result was released that she did not rule out suicide. She also said Mr. Milosevic had been thoroughly monitored by medical aides, and that it was "very strange, even if it is of course possible, that he should have died so suddenly without these medics having noticed a worsening of his condition."
The death of Mr. Milosevic sent shock waves through the tribunal, putting it on the defensive just as a defining moment in the history of the Yugoslav war crimes prosecutions appeared at hand. His death also raised a whole set of new issues for the United States and European Union, which had hoped that the conclusion of his four-year trial, with conviction widely expected, would help expedite resolution of other problems that are vestiges of Mr. Milosevic's catastrophic rule in the 1990's. A January report by the prison doctor that was disclosed Sunday by Zdenko Tomanovic, one of Mr. Milosevic's lawyers, said an antibiotic known as rifampicin, used to treat serious bacterial infections, like tuberculosis and leprosy, had been found in Mr. Milosevic's blood.
Marlise Simons contributed reporting from The Hague