There is no evidence to suggest that former Yugoslav President Slobodan Milosevic was poisoned, according to a United Nations investigation.
Slobodan Milosevic died at the detention unit in March
The Hague tribunal's report said he died of a heart attack - despite claims "in some segments of the media that he was the victim of murder".
Mr Milosevic died in his cell on 11 March while on trial for war crimes.
The report said security breaches did allow him to self-medicate but said he had received "proper care".
The UN report is based on the investigations by the Dutch public prosecutors, coroner and police.
Doctors from Serbia, Russia, France, Belgium and the Netherlands, who had treated him before or during his time in detention were also consulted by the inquiry.
"Nothing has been found to support allegations reported in some sections of the media that Mr Milosevic had been murdered, in particular by poisoning," the inquiry concluded.
"The results of the independent investigation by the Dutch authorities demonstrate that such allegations are entirely false."
The report ruled out suicide and added that Mr Milosevic had serious health problems before he arrived at the tribunal in 2003. He also refused to stop smoking or take exercise and often ignored medical advice.
It said medical opinion was divided over whether surgery could have prevented his death.
Mr Milosevic, aged 64, was believed to have died at around 0745 (0645 GMT) on 11 March.
Guards knocked on his door for an 0900 wake-up, but assumed he was still sleeping and left him alone until 1000 when they saw "that he was still lying on his bed".
"As he approached the bed he saw that Mr Milosevic's face was greyish in colour and that his arm was hanging over the side of the bed," says the report.
The guards tried to find a pulse, but realised the prisoner was dead.
The report adds that the unique arrangements established at the detention unit to enable Mr Milosevic to conduct his own defence compromised security.
"Because of these arrangements, Mr Milosevic was able to obtain medications not prescribed for him by treating doctors," the report said.
The inquiry said security deficiencies had been partially remedied, but recommended that care should be taken in similar cases in the future.