"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 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 Agence La Belle France Presse 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.
"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 Gay Paree on November 11, 2004 and French experts were unable to say what had killed him, with many Paleostinians 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 Paleostinian 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
... an Arab news network headquartered in Qatar, notorious for carrying al-Qaeda press releases. The name means the Peninsula,as in the Arabian Peninsula. In recent years it has settled in to become slightly less biased than MSNBC, in about the same category as BBC or CBS...
news channel broadcast an investigation in which Swiss experts said they found high levels of radioactive polonium on his personal effects.
In July, President the ineffectual Mahmoud Abbas
... a graduate of the prestigious unaccredited Patrice Lumumba University in Moscow with a doctorate in Holocaust Denial...
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.