A team of French scientists probing the death of Palestinian leader Yasser Arafat in 2004 do not believe he was poisoned, according to leaks from their report.
They have reportedly concluded he died after a "generalised infection".
A previous report by Swiss scientists said tests on his body showed "unexpected high activity" of polonium.
This "moderately" supported the theory, long believed by many Palestinians, that he was poisoned, the report said.
Arafat's widow, Suha Arafat, told reporters in Paris she was "upset by these contradictions by the best European experts on the matter."
Arafat, who led the Palestine Liberation Organisation (PLO) for 35 years and became the first president of the Palestinian Authority in 1996, fell violently ill in October 2004 at his compound.
Two weeks later he was flown to a French military hospital in Paris, where he died on 11 November 2004, aged 75.
Mr Arafat's official medical records say he died from a stroke resulting from a blood disorder. French doctors were not able at the time to determine what had caused the disorder.
His body was exhumed for testing last year amid continuing claims he was murdered. Many Palestinians have accused Israel of being behind his death, something which Israel has always denied.
The latest reported findings were "not a surprise", Israeli foreign ministry spokesman Yigal Palmor said.
Tawfiq Tirawi, head of the Palestinian Authority's inquiry into the death, told AFP: "We need to study the report. We can't take a position on it until we've looked at it."
In July 2012, an al-Jazeera documentary reported that scientists at the Swiss Institute of Radiation Physics had found "significant" traces of a highly radioactive and toxic material on personal effects given to Mr Arafat's widow Suha after his death, including his trademark keffiyeh scarf.
Mrs Arafat asked the Palestinian Authority to authorise the exhumation of his remains in order "to reveal the truth".
The Palestinian Authority granted French investigators and a team of Swiss scientists permission for the exhumation and to take samples for testing.
Russia also sent experts, and samples were sent to its Federal Medico-Biological Agency.
Mrs Arafat also filed a civil suit at a court in the Paris suburb of Nanterre, alleging that her husband was murdered by an unnamed "perpetrator X". French prosecutors began a murder inquiry in August 2012.
Last month, a forensic expert said that the levels of radioactive polonium found in Mr Arafat's remains by the Swiss scientists were 18 to 36 times higher than normal.
However, they said their findings could not categorically prove the theory that he was poisoned.
The Swiss scientists had stressed that they had been unable to reach a more definitive conclusion because of the time that had elapsed since Arafat's death, the limited samples available and the confused "chain of custody" of some of the specimens.
In November, Palestinian officials said the third report, by Russian experts, did not give "sufficient evidence" to support the decision that Mr Arafat was poisoned. However, experts who reviewed the document for al-Jazeera - which said it had obtained a copy - cast doubt on its findings.
Also on Tuesday, Mr Tirawi said he would soon name the people he believed were responsible for Mr Arafat's death.
"I promise that the next press conference will be the last and will cast into the light of day everyone who perpetrated, took part in or conspired in the matter," he told Palestine Today television, Reuters reports.