The network said Wednesday that Swiss scientists who tested the remains found relatively high levels of the radioactive element polonium, which could indicate Arafat was poisoned in 2004.
"Yasser Arafat died of polonium poisoning," said David Barclay, a British forensic scientist. "We found the smoking gun that caused his death. What we don't know is who's holding the gun at the time."
The testing on the remains from Arafat's exhumed body was conducted at the University Center of Legal Medicine in Lausanne, Switzerland. The team of Swiss scientists who obtained the samples a year ago issued a 108-page report that was obtained by al-Jazeera.
The report did not speculate on who might have poisoned Arafat and said the result "moderately supports" the notion he died from polonium poisoning. Polonium levels in the bone samples, however, were 18 times normal.
Arafat, 75, died in 2004 about a month after becoming violently ill after eating dinner at his compound in Ramallah. No autopsy was conducted and his rapid deterioration stirred up rumors on the West Bank that he had been murdered.
Arafat's doctor had initially diagnosed him with the flu; however al-Jazeera said tests run by the Swiss on his clothing also revealed elevated levels of the isotope polonium-10.