Wednesday's announcement by investigator Tawfik Tirawi, a former intelligence chief, came after weeks of zigzagging by Arafat's heirs over whether they would agree to dig up the remains.
Last month, a Swiss lab testing biological stains on Arafat's clothes detected elevated levels of radioactive polonium-210, reviving speculation about what killed Arafat. But the lab said the findings were inconclusive and that only testing Arafat's remains could bring clarity.
Lab officials have said polonium decays quickly and that an autopsy needs to be done soon. Darcy Christen, a spokesman for Switzerland's Institute of Radiation Physics, was not immediately reachable for comment Wednesday.