Ashrawi said she had spoken with Arafat's doctors, who told her that they could not rule out the possibility that he had been poisoned.
"But we didn't have any kind of thread, any kind of evidence," she told CNN in July. Referring to the report that showed polonium-210 on some of his belongings, Ashrawi said it "in many ways, tells us our suspicions are founded that there is sufficient evidence to say that he was killed, that he was assassinated using polonium."
Only a few countries, including the United States, Israel and Russia, have stocks of polonium-210, a fact that would limit the list of possible suspects, according to Cham Dallas, a professor and toxicologist at the University of Georgia's Institute for Health Management and Mass Destruction Defense.
"You would only use polonium if you were making a statement, not if you were trying to hide," he said.
Someone trying to get away with murder would be better off using pharmaceutical agents, since a number of of them "disappear in the body" and cannot be identified later, he said.
"I can't figure out why they would use it, frankly," he said. "There are so many really cool agents to kill people if you want to be secret and even if you want to make a statement."
Polonium-210 made headlines in 2006, when it was used to kill Alexander Litvinenko, a former KGB agent who came to Britain in 2000 after turning whistle-blower on the FSB, the KGB's successor.
In a deathbed statement from a London hospital, Litvinenko blamed Russia's President Vladimir Putin, an accusation the Kremlin strongly denied.
But it's hard to compare the cases of Arafat and Litvinenko, who was diagnosed when he was alive, Bochud said.
Arafat's symptoms when he died were not entirely consistent with polonium poisoning, he said.
"For example, the bone marrow stayed in good shape until (the) death of Arafat. In other cases of polonium poisoning, there is a decaying of the bone marrow," the medical expert said. "Another point, he did not lose his hair as would be expected in the case of polonium (poisoning)."
Scientists performed more than 50 measurements on the belongings between February and June, he said.
Palestinians who view Arafat as a symbol of resistance are also quite emotional about the suspicion he was poisoned.
Arafat won the Nobel Peace Prize in 1994, along with Israeli leaders Yitzhak Rabin and Shimon Peres, for their work on the Oslo accords in 1993. The Oslo agreement was perceived at the time as a breakthrough that could lead to an independent Palestinian state and a permanent peace with Israel.