A Palestinian woman walks past a mural depicting the late Palestinian leader Yasser Arafat in this 2012 file photo. [Photo/Agencies]

Swiss scientists have found evidence suggesting Yasser Arafat may have been poisoned with a radioactive substance, a TV station reported Wednesday, prompting new allegations by his widow that the Palestinian leader was the victim of a "shocking" crime.

Palestinian officials have long accused Israel of poisoning Arafat, a claim Israel has denied. Arafat died under mysterious circumstances at a French military hospital in 2004, a month after falling ill at his Israeli-besieged West Bank compound.

The findings reported Wednesday appear to be the most significant so far in an investigation into Arafat's death initiated by his widow, Suha, and the satellite TV station Al-Jazeera.

Last year, Switzerland's Institute of Radiation Physics discovered traces of polonium-210, a deadly radioactive isotope, on some of Arafat's belongings. Soil and bone samples were subsequently taken from Arafat's grave in the West Bank.

On Wednesday, the TV station published the Swiss team's 108-page report on the soil and bone samples. The results "moderately support the proposition that the death was the consequence of poisoning with polonium-210," the report said.

Repeated attempts to reach the main author, Patrice Mangin, or the Lausanne-based institute's spokesman, Darcy Christen, were unsuccessful Wednesday night.

Experts not connected to the report said the results support the case that Arafat was poisoned, but don't prove it.

Suha Arafat told Al-Jazeera she was stunned and saddened by the findings.

"It's a shocking, shocking crime to get rid of a great leader," she said.

She did not mention Israel, but suggested that a country with nuclear capability was involved in her husband's death. "I can't accuse anyone, but how many countries have an atomic reactor that can produce polonium?" she said.

Polonium can be a byproduct of the chemical processing of uranium, but usually is made artificially in a nuclear reactor or a particle accelerator. Israel has a nuclear research center and is widely believed to have a nuclear arsenal, but remains ambiguous about the subject.