The state forensics agency in Russia says former Palestinian leader Yasser Arafat died of natural causes, not radiation poisoning.
The agency has tested samples taken from the body after it was disinterred last year. Arafat, 75, died in 2004 officially of a stroke after a four-week illness.
French doctors at the time could not determine the origin of his illness, and no autopsy was carried out.
Swiss, French and Russian experts have since analysed body samples for traces of polonium, because of claims Arafat was poisoned.
The Russian finding agrees with that of the French, but the Swiss last month said their test results were consistent with radiation poisoning.
However, they said that was not absolute proof of the cause of death.