Alexei Navalny was murdered by Russia with a type of frog poison, the governments of the United Kingdom, Sweden, France, Germany and The Netherlands have concluded.

In a joint statement on Saturday, the NATO countries said they were "confident" the Russian dissident had been poisoned by the Russian government with a "lethal toxin" known as epibatidine, which is found in South American poison dart frogs. The frogs aren't native to Russia. 

"Russia claimed that Navalny died of natural causes. But given the toxicity of epibatidine and reported symptoms, poisoning was highly likely the cause of his death," the countries wrote. "Navalny died while held in prison, meaning Russia had the means, motive and opportunity to administer this poison to him." 

ALEXEI NAVALNY'S DEATH REPRESENTS MAJOR BLOW TO POLITICAL DISSENT IN RUSSIA

The conclusion was made based on samples taken from Navalny's body. 

Navalny, one of Russian President Vladimir Putin’s most powerful opponents, died in a Russian prison in Siberia in 2024 after he decided to go back to his home country in 2021.

Navalny was immediately detained upon his return to his home country on charges that included fraud and contempt of court that were widely considered to be politically motivated.

The activist was famously brought to a German hospital in 2020 to recover after Western powers, including the U.S., accused Russia of poisoning him with a nerve agent known as novichok that was developed by the Soviet Union.

RUSSIA AGREES TO ABIDE BY EXPIRED NEW START NUCLEAR ARMS LIMITS - AS LONG AS US DOES THE SAME

"Russia’s repeated disregard for international law and the Chemical Weapons Convention is clear," the statement said, adding that Russia was also widely believed to have used novichok in England in 2018, leading to the death of a British woman named Dawn Sturgess.

"These latest findings once again underline the need to hold Russia accountable for its repeated violations of the Chemical Weapons Convention and, in this instance, the Biological and Toxin Weapons Convention," the statement said.

The countries added that they had written to the director general of the Organisation for the Prohibition of Chemical Weapons to "inform him of this Russian breach of the Chemical Weapons Convention."