RAMALLAH, West Bank — The head of the Palestinian panel investigating the death of Yasser Arafat blamed Israel for his poisoning, saying the Jewish state was the "only suspect," and vowed to find out exactly what happened.

“We can confirm that Arafat did not die because of age or disease, he did not die a natural death,” Tawfiq Tirawi said at a news conference in Ramallah in the West Bank Friday. “We say again Israel is the only one involved in this. Israel is the first, fundamental, and only suspect in the assassination of Yasser Arafat."

Tirawu said the panel would approach the United Nations once its inquiries were complete.

A Swiss team that examined remains of the longtime Palestinian leader said yesterday its findings “moderately support” the hypothesis he was poisoned with polonium, while noting that the results were not definitive.

An Israeli government spokesman called the report more “soap opera than science.”

Arafat died on Nov. 11, 2004, at the age of 75. His remains were exhumed at the end of 2012 after his wife, Suha, requested an autopsy to search for traces of poison.

Palestinian groups have previously accused Israel of causing Arafat’s death, though they haven’t backed up that accusation with conclusive evidence. Israel denies killing him.

A similar medical report released by Russia’s Federal Medical-Biological Agency last month uncovered no trace of polonium in Arafat’s remains, the Interfax news agency reported on Oct. 16, citing the head of the agency.

The Associated Press contributed to this report