Yasser Arafat died of natural causes, not radiation poisoning, Russian scientists who examined his remains said on Thursday, but their findings were dismissed by Swiss experts as politically motivated.
The conclusions into the Palestinian leader's 2004 death dovetail with the findings of French investigators but differ from those of Swiss radiation experts who maintain he could have been poisoned.
The Palestinians have long suspected that Arafat was poisoned, with some pointing the finger directly at Israel.
"We have completed all the studies," Vladimir Uiba, head of Russia's Federal Medical-Biological Agency (FMBA), told reporters, adding "the person died a natural death and not from radiation".
Uiba said that his agency had not received any requests from the Palestinians to conduct a repeat examination, noting that " an expert evaluation was completed, and everyone agreed with us. Moreover, even the Swiss withdrew their statements and agreed, and the French confirmed our conclusions".
The director of the Lausanne Radiophysics Institute who examined the samples of Arafat's remains, immediately took issue with Uiba's statement, saying the position of the Swiss experts had remained the same.
Francois Bochud, criticized the Russian experts for not releasing their report, saying "our point of view has not changed, that's for sure" , stressing that "the Russians make claims without providing any data, without providing any scientific arguments, for me that is empty, a political declaration".
Bochud said the Swiss had not received a copy of the Russian study, and that Palestinian officials who had seen it said the results were similar to the Swiss data.
Bochud co-authored a report released in November that found high levels of polonium, up to 20 times the normal level, were found in samples taken from Arafat's body. The report said the findings were consistent with radioactive poisoning without saying conclusively Arafat's death was due to the polonium.
Spokesman for the Federal Medical-Biological Agency "Alexander Vlasov" told AFP the Russian experts had been tasked by the foreign ministry to carry out the investigation for the Palestinian authorities. He said it was up to the Palestinians to publish the report.
The Palestinian ambassador to Russia said the Palestinian authorities would press on with the probe.
Arafat remains were exhumed in November 2012, partly to investigate whether he had been poisoned with radioactive polonium, a suspicion that grew after the substance was used to assassinate Russian ex-spy and Kremlin critic Alexander Litvinenko in 2006.
Some 60 samples were taken and divided between Swiss and Russian investigators as well as a French team carrying out the probe at the request of Arafat's widow, Suha. The French have also ruled out radioactive poisoning.
Suha Arafat has told AFP that she was "completely convinced that the martyr Arafat didn't die a natural death".