It followed the deposition of a civil suit in late July by Arafat’s widow, Suha, after a Swiss forensic institute found unexpected traces of polonium-210 on his clothes and other personal effects preserved by his wife.
Hanan Ashrawi, a member of the Palestine Liberation Organisation’s executive committee, said: “We welcome the fact that the French want to open an investigation and we think it’s about time for it. It should have been opened a long time ago.
“It has to be investigated because there is evidence the death was not natural and there are all sorts of question marks and proof of foul play. We have been suspecting Israeli involvement for a long time. We need closure and we need to find out what happened.”
The French investigation is likely to add impetus to plans by the Palestinian Authority to exhume Arafat’s body from the stone-clad mausoleum in which he is buried in the presidential compound in Ramallah.
The authority, in response to a plea from Mrs Arafat, said last month it was willing to order an exhumation after the results of the Swiss investigation.
Arafat, who for years led the PLO’s fight for Palestinian independence, fell ill after he had been besieged in Ramallah by Israeli tanks for more than two years during the second Palestinian intifada, or uprising. He was airlifted to a military hospital in the French capital where he died.
French doctors were unable to verify the cause of death, stirring claims of foul play. The reports of the presence of polonium on his effects, including his trademark headscarf, were particularly potent because the lethal radioactive substance was used to kill Alexander Litvinenko, a former Russian spy, in London in 2006.
A statement by Mrs Arafat’s lawyers in Paris welcomed the decision by the court in the western suburb of Nanterre. It said they would make no further comment to allow the investigating judges to pursue their probe with respect for secret information and without undue interference.
Lawyers said the investigation, which could involve up to three judges, was the first step towards deciding whether there was a murder case to answer. The case brought by Mrs Arafat and her daughter does not name an alleged killer, but is brought against an unnamed perpetrator X.
Yigal Palmor, spokesman for the Israeli foreign ministry, said the case “does not pertain to us”, adding: “If the French justice system has decided to open an investigation, we hope that it will shed light on this matter.”