Professor David Barclay, a British forensic scientist retained by Al Jazeera to interpret the results of the Swiss tests, said the findings from Arafat's body confirmed the earlier results from traces of bodily fluids on his underwear, toothbrush and clothing.
In my opinion, it is absolutely certain that the cause of his illness was polonium poisoning. The levels present in him are sufficient to have caused death.
What we have got is the smoking gun - the thing that caused his illness and was given to him with malice.
Barclay said no one would have thought to look for polonium as a possible poison until the Litvinenko case, which occurred two years after Arafat's death.
"We are revealing a real crime, a political assassination," Suha Arafat told Reuters.
"This has confirmed all our doubts," said Suha Arafat. "It is scientifically proved that he didn't die a natural death and we have scientific proof that this man was killed."
She did not accuse any country or person, and acknowledged that the historic leader of the Palestine Liberation Organization had many enemies.
An investigation by the Qatar-based Al Jazeera television news channel first reported last year that traces of polonium-210 were found on personal effects of Arafat given to his widow by the French military hospital where he died.
Palestinian leader Yasser Arafat was poisoned to death in 2004 with radioactive polonium, his widow Suha said after receiving the results of Swiss forensic tests on her husband's corpse.
A team of experts, including from Lausanne University Hospital's Institute of Radiation Physics, opened Arafat's grave in the West Bank city of Ramallah last November, and took samples from his body to seek evidence of alleged poisoning.