The remains of Yasser Arafat have been exhumed, Palestinian officials say, as part of an investigation into how the Palestinian leader died.
Swiss, French and Russian experts will take samples to establish whether his death, at a military hospital in Paris in 2004, was the result of poisoning.
France began a murder inquiry in August after Swiss experts found radioactive polonium-210 on his personal effects.
Arafat's medical records say he had a stroke resulting from a blood disorder.
His widow, Suha, objected to a post-mortem at the time, but asked the Palestinian Authority to permit the exhumation "to reveal the truth".
Arafat's body lay in a stone-clad mausoleum inside the Muqataa presidential compound in the West Bank city of Ramallah. The mausoleum was sealed off earlier this month.
Palestinian officials told the Associated Press that the remains were taken from the mausoleum to a nearby mosque, so that Palestinian doctors could take samples from the bones.
With the body removed from the tomb, the scientists will each take samples and then go to their respective countries to carry out tests for polonium-210 and possibly other lethal substances.
It is believed that the investigation could take several months.
Before the exhumation, the head of the Palestinian committee investigating Arafat's death, Tawfik al-Tirawi, said no journalists would be allowed to observe the exhumation.
"Because [of the] sanctity of the symbol and the sanctity of this event, [the exhumation] should not be permitted to be in front of the media," the former Palestinian intelligence chief said.
A reburial ceremony, with full military honours, is expected to take place later on Tuesday.
Many Palestinians continue to believe Arafat was poisoned by Israel, which saw Arafat as an obstacle to peace and had put him under house arrest. Israel has strongly denied any involvement.
Arafat, who led the Palestine Liberation Organisation for 35 years and became the first president of the Palestinian Authority in 1996, fell violently ill in October 2004 inside the Muqataa.
Two weeks later he was flown to a French military hospital in Paris, where he died on 11 November 2004, aged 75.
In 2005, the New York Times obtained a copy of Arafat's medical records, which it said showed he died of a massive haemorrhagic stroke that resulted from a bleeding disorder caused by an unknown infection.
Independent experts who reviewed the records told the paper that it was highly unlikely that he had been poisoned.
A murder inquiry was launched by French prosecutors in August after an investigation by al-Jazeera TV, working with scientists at the Institute of Radiation Physics (IRA) at the University of Lausanne in Switzerland, found "significant" traces of polonium-210 present in samples taken from Arafat's personal effects, including his trademark keffiyeh headdress.
In some cases, the elevated levels were 10 times higher than those on control subjects, and most of the polonium could not have come from natural sources, the scientists said.
But the institute also said that Arafat's symptoms - as described in his medical records - were not consistent with polonium poisoning.
The former Russian spy Alexander Litvinenko died of exposure to polonium-210 in London in 2006. The UK authorities have accused Andrei Lugovoi, an ex-KGB officer, of poisoning his tea.