Work began on Tuesday to open former Palestinian President Yasser Arafat's grave ahead of an exhumation of his body for a murder probe, AFP reported.A source close to Arafat's family told AFP that work is expected to last 15 days, and that it began on Tuesday with removing concrete and stones from Arafat's mausoleum.French, Swiss and Russian experts are due to exhume Arafat's body in Ramallah in an attempt to discover how he died after an Al Jazeera documentary in July suggested he was killed by a rare radioactive poison.Allegations of foul play have long surrounded the demise of Arafat.The case returned to the headlines in July when a Swiss institute said it had discovered high levels of the radioactive element polonium-210 on Arafat's clothing supplied by his widow Suha, who called for exhumation of her husband's body.Polonium is the radioactive substance found to have killed former Russian spy Alexander Litvinenko in London in 2006.Three French forensic experts are expected to visit Arafat's limestone sepulchre in the West Bank capital of Ramallah on November 20, and investigating magistrates plan to visit four days later, according to a diplomatic source.Arafat's direct kin have rejected an exhumation. "We say openly that our leader, our founder was assassinated by Israel with poison. The overwhelming majority of the Palestinian people is convinced of this," Nasser al-Kidwa, Arafat's nephew and a senior official in Abbas's Fatah group, said on Saturday."Some have spread about the repugnant idea that Arafat's tomb should be opened up and desecrated. There is no justification for this: we know the real truth," he said.Arafat's sister also called on officials not to exhume his Ramallah grave, Palestinian news agency Ma'an reported.