The Yasser Arafat Foundation said Sunday there was "no need" for more proof the Palestinian leader was poisoned in what appeared to be a stance against French plans to exhume his body.
"Since the formation of this Foundation, it has forcefully held on to the fact that Yasser Arafat died abnormally after being killed by a poison which was unidentified at the time," it said in a statement.
"The Foundation does not see a need here for more proof."
The statement was issued just days after a delegation of French magistrates said they would travel to travel to the West Bank to investigate following claims Arafat may have succumbed to poisoning by the radioactive substance polonium.
No date has been given for the trip which would involve forensic officers exhuming the body and taking samples for laboratory testing in an investigation sought by Arafat's widow Suha.
Speaking to AFP on condition of anonymity, a source from the Foundation said they would only agree to a further examination of his body if it was conducted as part of an international investigation committee.
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"If there is an international committee, we will agree to the body being checked," he said, without explaining further.
Arafat died in a French military hospital near Paris on November 11, 2004 and French experts were unable say what had killed him, with many Palestinians subscribing to the belief that he was poisoned by Israel.
Arafat's nephew, Nasser al-Qidwa, who heads the Arafat Foundation, has long insisted that Israel was behind his uncle's death but a Palestinian investigation into such allegations ruled out poisoning, AIDS and cancer.
Last month, French prosecutors opened a murder inquiry into Arafat's death after Al-Jazeera news channel broadcast an investigation in which Swiss experts said they found high levels of radioactive polonium on his personal effects.
In July, president Mahmud Abbas and Suha Arafat both gave their consent for samples to be taken from his remains, which are buried in a mausoleum in the West Bank city of Ramallah.
But some Palestinians feel the French did not do enough to shed light on the cause of Arafat's death at the time and they are pushing for an international probe into the circumstances of his death.