Digging up Yasser Arafat's bones may offer the best shot at learning if the legendary Palestinian leader was poisoned, as many of his old comrades-in-arms claim, but Palestinian officials signaled Thursday they're not rushing into an autopsy.

Arafat's 2004 death remains shrouded in mystery, and this week's findings by Switzerland's Institute of Radiation Physics — that belongings linked to Arafat contained an elevated level of a radioactive agent — have revived speculation about foul play.

However, the institute said more tests are needed, prompting Arafat's widow Suha to demand that her husband's remains, buried under a glass-and-stone mausoleum in his former West Bank compound, be exhumed.

Arafat's successor, President Mahmoud Abbas, has agreed to an autopsy in principle, but it seems a final decision will take time.

Abbas aide Nimr Hamad said Thursday that a team of experts would first be sent to Europe to learn more from the Swiss institute and from the French military hospital where Arafat died on Nov. 11, 2004.

Another possible hurdle is consent by Arafat's close relatives, particularly his nephew Nasser al-Kidwa, a former Palestinian envoy to the United Nations and — as head of the Yasser Arafat Foundation — the custodian of his uncle's memory.

Earlier this week, al-Kidwa seemed cool to the idea of an autopsy, telling the Arab satellite TV station al-Jazeera that he believes the findings by the Swiss institute are sufficient proof of his long-standing claim that Arafat was poisoned. Al-Kidwa has not been reachable for comment since then. Abbas has said he'll only order an autopsy if the family is on board, but did not define whom he meant.

A full-blown investigation could lead to uncomfortable questions for the Palestinian leadership. Fingers have been pointed at Israel, but if an autopsy were to reveal that Arafat was indeed poisoned, the probe would also have to look at Palestinians who had access to him.

In the last three years of his life, Arafat was confined by Israel to his walled compound in the city of Ramallah, the Muqata. The Palestinian leader was seen by Israel and the U.S. as an obstacle to peace efforts and a sponsor of attacks that killed hundreds of Israelis.

Israel has emphatically denied a role in Arafat's death. "Israel did not kill him, I say that with certainty," Dov Weisglas, a high-powered aide to then-Israeli Prime Minister Ariel Sharon, told Israel TV on Thursday. Weisglas said that by that time, Arafat had already been marginalized. Israel had many chances over the years to assassinate Arafat, but decided not to, Weisglas added.

In the fall of 2004, after the 75-year-old Arafat fell violently ill at his compound, Weisglas was among those negotiating with Palestinian officials over the terms of the besieged leader's departure for medical treatment abroad.

"The man was very, very sick," Weisglas said of Arafat. He said one of the Palestinian interlocutors warned him at the time that if Arafat died in his compound, "just like for 2,000 years you had to prove you didn't crucify Jesus, then for another 2,000 years you will have to prove you didn't kill Arafat."

The former Sharon aide also suggested Arafat may have been killed by a medical mistake at the French military hospital. "What happened in France is they gave him a partial blood infusion, he recovered, then they gave him a full blood transfusion," Weisglas said. "That was probably a medical mistake, and he went into shock and never recovered."

Senior French military doctor Denis Gutierrez said Thursday that he cannot comment on such claims because of French medical privacy laws. He said any information about a blood transfusion would be in the medical report that was submitted to Arafat's family.

At the time, French doctors said Arafat died of a massive stroke. According to French medical records, he had suffered inflammation, jaundice and a blood condition known as disseminated intravascular coagulation, or DIC.

But the records were inconclusive about what brought about the DIC, which has numerous possible causes, including infections and liver disease. Outside experts who reviewed the available records on behalf of The Associated Press were also unable to pinpoint the underlying cause.

The Arafat-linked belongings tested by the Swiss institute were provided by his widow, who is estranged from most of the Palestinian leadership and has lived outside the Palestinian territories since before her husband's death. Mrs. Arafat has not explained why she waited this long to have the tests done, but was cooperating with Al-Jazeera, which first broadcast the findings on Tuesday.

The Swiss institute detected elevated traces of the radioactive substance polonium-210 — extremely lethal in small doses — on Arafat's belongings, including a toothbrush, a fur hat and underwear. Polonium's most famous victim is KGB agent-turned-Kremlin-critic Alexander Litvinenko, who died in 2006 after losing all his hair and turning blue — symptoms not displayed by Arafat.

Derek Hill, a radiological science expert at University College London, has said despite the natural decay of the substance after eight years, an autopsy should be able to tell "with a pretty high confidence" whether Arafat had polonium in his body when he died.

Exhuming remains, particularly of a revered leader like Arafat, could potentially offend the sensibilities of ordinary Palestinians, though the top Muslim cleric in the Palestinian territories has said religion would not stand in the way of an autopsy.

At the same time, the circle of those seeking a thorough investigation widened, with Tunisia asking the Arab League to hold a ministerial meeting to discuss the circumstances of Arafat's death.

Hanan Ashrawi, a senior PLO official, said Abbas assured her he would cooperate with any investigation.

"We want to know. We want closure," she said. "This was not an ordinary man."

Joining the chorus Thursday was Ismail Haniyeh, prime minister of the Gaza Strip government run by Arafat's rival, the Islamic militant Hamas.

"We support the extraction of the body of the late President Arafat for re-examination in order to discover the elements who facilitated the assassination," he told an audience in Gaza.