Alexei Navalny, who died in an Arctic prison camp two years ago, was murdered by the Russian state using a powerful frog toxin, the governments of Germany, Britain, Sweden and the Netherlands said on Saturday.
The countries said analyses of Navalny's remains showed traces of the highly potent toxin epibatidine, and accused Moscow of killing Russian President Vladimir Putin's biggest foe.
The announcement was made by German Foreign Minister Johann Wadephul and his counterparts on the sidelines of the Munich Security Conference, where dozens of world leaders and top defence officials have gathered for three days of talks.
Navalny's widow, Yulia Navalnaya, who was present at the announcement, said the findings proved that Putin was a murderer.
Wadephul said the new analyses had clarified the cause of death. "Alexei Navalny was poisoned in Russian custody," he said.
According to the German minister, the remains contained epibatidine, an extremely potent nerve toxin found in the skin secretions of certain poison dart frogs in Ecuador.
He said the substance was about 200 times stronger than morphine and paralysed the respiratory muscles, causing victims to suffocate.
It was not immediately clear when, where or how the analyses were carried out.
Navalny's death in February 2024 prompted international condemnation and accusations from Western governments that the Kremlin was responsible. Moscow has repeatedly denied involvement in his death.
