Many Palestinians have long believed Israel killed him - a charge Israel flatly denies - but an official Palestinian Authority investigation headed by Tawfiq Tirawi has yet to produce any evidence.
Arafat, who signed the 1993 Oslo interim peace accords with Israel but then led an uprising in 2000, died at 75 in a French hospital four weeks after falling ill following a meal in his Ramallah compound surrounded by Israeli tanks.The official cause of death was a massive stroke, but French doctors said at the time they were unable to determine the origin of his illness. No autopsy was carried out.Swiss forensic experts said last month that their tests of samples taken from Arafat's body were consistent with polonium poisoning, while not absolute proof of the cause of death.Samples were taken from Arafat's body in November 2012 by Swiss, French and Russian experts after an al Jazeera documentary said his clothes showed high amounts of polonium.