Yasser Arafat was not the victim of poisoning, French forensic scientists concluded on Tuesday, countering a Swiss report on the 2004 death of the Palestinian leader that found he was probably killed with radioactive polonium.

The French conclusions were immediately challenged by his widow, Suha Arafat, who has argued the death was a political assassination by someone close to her husband. A senior Palestinian official dismissed the report as "politicized".

"You can imagine how much I am shaken by the contradictions between the findings of the best experts in Europe in this domain," Suha Arafat, dressed in black and reading from a written statement, told a news conference in Paris.

"I am accusing no one. This is in the hands of justice and it is just the beginning," she said, requesting that the Swiss report be made available to French magistrates examining the case following a legal complaint she filed.

Separately, the French public prosecutor involved in that case confirmed the investigation would continue.

Arafat, who signed the 1993 Oslo interim peace accords with Israel but then led an uprising after subsequent talks broke down in 2000, died aged 75 in a French hospital in November 2004. His death came four weeks after he fell ill after a meal, suffering from vomiting and stomach pains.

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 stirred controversy last month by announcing that results from their tests of samples taken from Arafat's body were consistent with polonium poisoning, while not absolute proof of the cause of death.

The report handed to Suha Arafat will not be published, but the French public prosecutor's office said it concluded: "In sum, death was not due to poisoning with Polonium 210...

"Measurements of Polonium 210 and other radioactive substances taken from biological samples of the body are consistent with a natural environmental origin."

That could lead the magistrates to close the case, unless they have other incriminating evidence.

A Palestinian official dismissed the French findings.

"The French report is politicized and is contrary to all the evidence which confirms that the president was killed by poisoning," senior Palestinian official Wasel Abu Yousef told Reuters in Ramallah.

"This report is an attempt to cover up what happened in Percy hospital," he said of the French military hospital near Paris where Arafat was taken for treatment in 2004.

Many Palestinians believe Israel killed him - a charge Israel denies. Earlier, a Palestinian investigator said he would soon name the people he believed were behind Arafat's death, almost a decade after he started searching for suspects.

"We are in the last 15 minutes of the investigation," Tawfiq Tirawi told Palestine Today television.

There are few known cases of polonium poisoning, the most famous recent example being that of defecting Russian spy Alexander Litvinenko, who drank a poisoned cup of tea in a London hotel in 2006.

"We have no doubt that the most comprehensive and thorough report that examined all aspects of this case remains the Swiss report," Suha Arafat's lawyer Saad Djebbar told Reuters, calling it "the only show in town".

A radiation scientist who examined the Swiss and the French reports for Suha Arafat said both studies had found similar levels of Polonium 210 in Arafat's body but differed in their explanations of how it got there.

The French report concluded that some of the radioactivity could be explained by the presence of radon gas in the tomb where Arafat was buried. The Swiss experts said on the contrary that the level of radon gas was due to the radioactivity in his body.-Reuters