Workers are seen on the scaffolding holding up the tarpaulin obscuring the entrance to the mausoleum of the late Palestinian leader Yasser Arafat, on November 27, 2012, at the Muqataa in the West Bank city of Ramallah.(ABBAS MOMANI/AFP/Getty Images)

Yasser Arafat’s bones contain 18 times the normal amount of the radioactive substance polonium-210, indicating that the Palestinian leader was poisoned, according to the results of a Swiss lab test shared with Arafat’s widow, Reuters reports. Forensic scientist Dave Barclay told Al Jazeera that the new results convinced him that Arafat was, in fact, murdered.

“Yasser Arafat died of polonium poisoning,” he said. “We found the smoking gun that caused his death. What we don’t know is who’s holding the gun at the time.”

“The level of polonium in Yasser Arafat’s rib…is about 900 millibecquerels,” Barclay said. “That is either 18 or 36 times the average, depending on the literature.”

Arafat died suddenly in 2004 at 75 years old, falling ill shortly after eating dinner. The suspicious circumstances caused some to cry foul, prompting an investigation into his death. Since then, whether or not Arafat was poisoned has long been the subject of debate.

In an oft-cited 2012 Foreign Policy article titled Arfatuous, Hussein Ibish, a senior fellow at the American Task Force on Palestine, argued that the polonium poisoning claims were bogus:

First and most importantly, Arafat’s symptoms are well documented and completely inconsistent with 210PO (polonium) poisoning. Unlike Litvenenko, he didn’t lose his hair and his bone marrow was found to be undamaged. He also staged at least one brief recovery, which wouldn’t be possible in the case of polonium poisoning. It should be added that his symptoms were also completely inconsistent with AIDS.

Second, the Swiss lab report on which the Al Jazeera story relies, clearly states that its findings are inconclusive and provide no basis for concluding polonium poisoning, especially since his symptoms were inconsistent with that. The report also states that further testing may reveal that the 210PO levels detected may prove to have been naturally occurring, albeit unusually high.

Third, the provenance of the items in question is not well-established, and therefore the relationship between the 210PO levels discovered on them and Arafat’s condition is very much in doubt. Even an exhumation of the body, which the Palestinian Authority (PA) is reportedly considering, may not prove conclusive, as 210PO has a very short half-life of 137 days.

Last November, a team of forensic experts exhumed Arafat’s body after atypical level of polonium were found in his clothing and personal belongings. If Arafat was indeed murdered, the next big question is who killed him. Though Arafat, a notorious partner in the failed Oslo Accords, had no shortage of enemies, his supporters were quick to accuse Israel, which has long denied any wrongdoing, of his death.

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