Recent tests conducted on Yasser Arafat's personal belongings at the time of his unexpected death in 2004 suggest his body contained abnormal levels of radioactive polonium, the same poisonous substance that killed Russian spy-turned-dissident Alexander Litvinenko, Al-Jazeera TV reports.

Al-Jazeera says its nine-month investigation found that Arafat was in good health until he fell suddenly ill Oct. 12, 2004, at his compound in Ramallah on the West Bank. He was flown to a French miitary hospital in Paris, where he died several days later.

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No autopsy was performed on the longtime Palestinian leader, who died at the age of 74.

Al-Jazeera says the tests on his clothes, including his toothbrush and kaffiyeh, were conducted by the Institut de Radiophysique in Lausanne, Switzerland.

"I can confirm to you that we measured an unexplained, elevated amount of unsupported polonium-210 in the belongings of Mr. Arafat that contained stains of biological fluids," Francois Bochud, the director of the institute, tells Al-Jazeera.

Additional tests, conducted over a three-month period from March until June, concluded that most of that polonium found in samples of body fluids -- sweat and urine -- on Arafat's clothes, was "unsupported," meaning that it did not come from natural sources.

Al-Jazeera says there is little scientific consensus on the symptoms of polonium poisoning, mostly because it is so rare.

Litvinenko suffered severe diarrhea, weight loss and vomiting, as did Arafat, in the days and weeks before he fell ill.

A British inquiry into the Litvinenko's death found that he was poisoned with polonium slipped into his tea at a sushi restaurant, Al-Jazeera notes.