Arafat polonium findings confirmed by Swiss scientists
Swiss scientists have confirmed that tests show the late Palestinian leader Yasser Arafat had high levels of radioactive polonium in his body.
However, they could not say whether polonium poisoning had caused his death in 2004.
Their report concluded that Arafat's remains showed levels of polonium 18 times higher than normal.
Arafat's widow, Suha, has reaffirmed to the BBC her belief that their report proves he was assassinated.
But she said she could not directly accuse anyone, saying that he had many enemies around the world.
The Swiss scientists were extremely cautious about their findings.
Testing for polonium 210 so many years after Yasser Arafat's death is fraught with difficulties.
It is a very unstable element, with a half-life of 138 days.
That means after four months, the amount of polonium in a sample would have halved; after a year there would be just one eighth of the original amount; and after the eight years since Mr Arafat died, there would be a vanishingly small fraction remaining.
This adds huge levels of uncertainty to any findings - as does the fact that polonium is also found naturally in the soil and air.
Many Palestinians have long believed that Israel poisoned Arafat. There have also been allegations that he had Aids or cancer. Israel has consistently denied any involvement.'Documented for history'
The scientists - from the Vaudois University Hospital Centre (CHUV) in Lausanne, Switzerland - had carried out a detailed examination of Arafat's medical records, samples taken from his remains and items he had taken into the hospital in Paris where he died in 2004.
The biological materials included pieces of Mr Arafat's bones and soil samples from around his corpse.
Professor Francois Bochud told a news conference on Thursday that the high level of polonium detected "by definition... indicates third party involvement... Our results offer moderate backing for the theory of poisoning."
But he went on to say: "Was polonium the cause of the death for certain? The answer is no, we cannot show categorically that hypothesis that the poisoning caused was this or that."
Swiss scientists' findings
- Experts at the Vaudois University Hospital Centre (CHUV) in Lausanne, Switzerland, conducted tests on samples taken from Yasser Arafat's exhumed body in November 2012
- Samples also analysed by Palestinian, French and Russian teams, whose findings have yet to be published by the Palestinian Authority
- Swiss report says "unexpectedly high levels of polonium-210 and lead-210 activity" found in specimens taken from Arafat's ribs, pelvis and soil that absorbed his bodily fluids
- It notes a lack of adequate biological specimens, particularly soft tissues, and the eight years between death and the investigation, rendering detection subject to uncertainties
- But it concludes results "moderately support the proposition that the death was the consequence of poisoning with polonium-210"
In their report, the 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.
Polonium-210 is a highly radioactive substance. It is found naturally in low doses in food and in the body, but can be fatal if ingested in high doses.
Arafat, who led the Palestine Liberation Organisation for 35 years and became the first president of the Palestinian Authority in 1996, fell violently ill in October 2004 at his compound in the West Bank.
Two weeks later he was flown to a French military hospital in Paris, where he died on 11 November 2004, aged 75.
His official medical records say he died from a stroke resulting from a blood disorder.
France began a murder inquiry in August 2012 after the preliminary findings of polonium by the Lausanne scientists, who have been working with an al-Jazeera documentary crew.
- Highly radioactive and toxic element
- Present in foods in low doses
- Low levels found naturally in the environment
- Can be manufactured by bombarding certain isotopes with neutrons
- Has industrial uses such as in anti-static devices
- Very dangerous if significant dose ingested
- External exposure not a risk, only if ingested
- Present in tobacco
Parallel investigations are being carried out by French and Russian experts - one Russian official said last month that no traces of polonium had been found.
Suha Arafat, who had objected to a post-mortem at the time of his death, agreed for his body to be exhumed a year ago "to reveal the truth".
Welcoming the Swiss report, Mrs Arafat said she had no doubt that her husband had been assassinated but refused to point the finger at Israel.
"I can't accuse anybody. Everybody wants to accuse Israel - I can't accuse - I can't jump into conclusion," she told the BBC.
"Now the case is in the French jurisdiction, I wanted to document this crime - this crime I want it documented for history, actually."