President Bill Clinton, center, Israeli Prime Minister Ehud Barak, left, and Palestinian leader Yasser Arafat walk on the grounds of Camp David, Md., on July 11, 2000, at the start of the Mideast summit. (RON EDMONDS/ASSOCIATED PRESS)

JERUSALEM — The Palestinian leadership signalled on Wednesday that it was ready to exhume the body of Yasser Arafat, in an attempt to investigate claims that the Palestinian leader, who died more than seven years ago, may have been poisoned with polonium, a highly radioactive substance.

“The [Palestinian] Authority, as it always has been, is ready to completely co-operate with and clear the way for an investigation into the true causes leading to the martyrdom of the late president,” said Nabil Abu Rudeinah, the authority’s spokesman.

His statement came in response to a surprise plea by Arafat’s widow to open his grave and submit the body to a fresh round of forensic tests. Though his remarks stopped short of formally agreeing to Suha Arafat’s request, Palestinian officials said privately there was no reason for the Palestinian Authority to stand in the way of an exhumation.

The causes of Arafat’s death in November 2004 have long been shrouded in secrecy and speculation. Many Palestinians believe he was poisoned, though no-one has yet produced clear evidence pointing to outside interference.

The debate gained fresh momentum on Tuesday night, when the al-Jazeera news channel broadcast a new investigation into Arafat’s death. It revealed the findings of a Swiss forensic institute that examined some of his belongings preserved by his widow.

A file photo taken on October 28, 2004 shows the widow of Palestinian leader Yasser Arafat, Suha, talking on the phone. (SEBASTIAN SCHEINER/AFP/GETTY IMAGES)

According to al-Jazeera, the scientists found unexplained traces of polonium-210 in his clothes and other effects used by the former leader after he fell ill. The institute also concluded that the levels of polonium found in his belongings were unusually high – up to 10 times higher than in control tests.

The Lausanne-based institute issued its own statement on Wednesday, confirming it had found an “unexplained amount of polonium-210” on Arafat’s personal effects. However, it cautioned that the results were “not sufficient to determine the cause of death.” The institute also pointed out that any interpretation of its results was difficult, not least because of the long time that had passed between Arafat’s death and the laboratory tests.

Polonium is the lethal radioactive substance that was used in the high-profile assassination of Alexander Litvinenko, a former Russian spy, in London in 2006. The discovery of the same substance on Arafat’s clothes, hat and trademark Kaffiyeh headscarf is likely to trigger speculation that the former Palestinian leader may have fallen victim to a comparable plot.

Arafat fell gravely ill after his presidential headquarters were besieged by Israeli tanks during the second Palestinian intifada, or uprising. He was then flown to Paris, where he died in a military hospital on Nov. 11, 2004.

Arafat lies buried in a stone-clad mausoleum that forms part of the presidential compound in the West Bank city of Ramallah.

Speaking to al-Jazeera, Suha Arafat said she wanted her late husband to be exhumed to finally uncover the truth. “Of course, after this result of the investigation, I would like to exhume, to ask the Palestinian Authority to help me and to help all the Palestinian people to exhume the body,” she said.

— Financial Times