RAMALLAH, West Bank — Yasser Arafat’s body might be exhumed to allow for more testing of the causes of his death, the Palestinian president said after a Swiss lab said it found elevated levels of a radioactive isotope in belongings the Palestinian leader is said to have used in his final days.

Arafat’s widow, Suha, called for an autopsy in the wake of the lab’s findings, first reported by the Arab satellite TV station Al-Jazeera. In an interview, she did not explain why she waited nearly eight years to have the belongings, including a toothbrush and a fur hat, tested. At the time of his death, she refused to agree to an autopsy.

The Palestinian leader died at a military hospital outside Paris in November 2004 of what French doctors called a massive brain hemorrhage — weeks after he fell violently ill at his West Bank compound.

Doctors, including independent experts who reviewed his medical records on behalf of The Associated Press, have been unable to pinpoint the underlying cause of the hemorrhage. Speculation has lingered in the Arab world that he was killed by Israel, which viewed him as an obstacle to a peace treaty. Israeli officials have vociferously denied any foul play.

Francois Bochud, who heads the Institute of Radiation Physics in Lausanne, Switzerland, told The Associated Press on Wednesday that his lab examined belongings that Arafat’s widow said were used by Arafat in his final days, as well as others that he hadn’t worn. Suha Arafat said the belongings were put in a secure room at her attorney’s office in Paris after Arafat’s death and stayed there until Al-Jazeera approached the lab on her behalf at the beginning of this year, he added.

Experts found what Bochud characterized as “very small” quantities of polonium, an isotope that is naturally present in the environment. But there were higher quantities of polonium in Arafat’s underwear and hospital clothing.

This would not necessarily mean Arafat was poisoned, Bochud said, adding that it is not possible to say where the polonium might have come from.

Polonium is best known for causing the death of Alexander Litvinenko, a one-time KGB agent turned critic of the Russian government, in London in 2006. Litvinenko ingested tea laced with the substance.

Palestinian President Mahmoud Abbas said he is willing to cooperate with further testing, provided Arafat’s family agrees.