Traces of the radioactive poisonous element polonium have been found in the belongings of late Palestinian President Yasser Arafat, according to the Swiss-based Institute of Radiophysics .

An Institute spokesman told Reuters news agency “surprisingly'' high levels of polonium-210 were found in Arafat's belongings. But he stressed clinical symptoms described in Arafat's medical reports were not consistent with polonium-210 poisoning.

Institute director Francois Bochud told al-Jazeera television the only way to confirm whether the Palestinian leader, who died in 2004, was poisoned with polonium would be to exhume Arafat's body.

Arafat's widow, Suha, told al-Jazeera she would ask for his body, buried in the West Bank town of Ramallah, to be exhumed.

Arafat, a Nobel Peace Prize winner who led the Palestinian Liberation Organization for nearly four decades, died at age 75 in a Paris hospital following several weeks of treatment. Citing privacy laws, French officials refused to reveal the precise cause of death, fueling rumors and theories as to the cause of his illness.

Polonium was found to have caused the death of former Russian spy Alexander Litvinenko in London in 2006, and he was assumed to have been deliberately poisoned.