A team of French scientists probing the death of Palestinian leader Yasser Arafat in 2004 says it is most likely that he died of natural causes, according to leaks to French media.
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.
Mr Arafat’s official medical records say he died in 2004 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.
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.
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 to exhume Arafat’s body and 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 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 lapsed since Arafat’s death, the limited samples available and the confused “chain of custody” of some of the specimens.