Deceased Kremlin critic Alexei Navalny was killed by a lethal toxin produced from poison ‌dart frogs ⁠in South America, according to five European governments.

Navalny openly criticised Russian President Vladimir Putin and was jailed in an Arctic penal colony, where he died in February 2024.

An analysis of samples from Navalny’s body confirmed the presence of epibatidine, a toxin not found naturally in Russia, said UK and European allies.

Britain, France, Germany, Sweden and the Netherlands said the results “conclusively” showed he had been poisoned with a lethal toxin.

“Only the Russian state had the means, motive and opportunity to deploy this lethal toxin to target Navalny during his imprisonment in a Russian penal colony in Siberia, and we hold it responsible for his death,” said their statement.

“Epibatidine can be found naturally in dart frogs in the wild in South America. Dart frogs in captivity do not produce this toxin and it is not found naturally in Russia.

“There is no innocent explanation for its presence in Navalny’s body.”

National Geographic states that poison dart frogs are one of the most toxic or poisonous species on Earth, found in rainforests in Central and South America.

They come in bright colours like red, orange, yellow, green and blue.

Russian opposition leader Alexei Navalny died while being held in an Arctic penal colony.

Russia ​has been reported to the Organisation on the Prohibition of Chemical Weapons over the breach, the statement issued in London said.

The Russian government has repeatedly denied any responsibility for Navalny’s death.

Navalny died in an Arctic prison colony ⁠in February 2024, and was convicted of ‌extremism ​and other charges, all of which he denied. His team and his ​widow Yulia Navalnaya ‌have since accused Putin of ordering his murder.

He died “while held in prison, ​meaning Russia had the means, motive and opportunity to administer this poison to him,” the joint statement said, adding that the findings ​showed ​Russia needed to be held accountable ​for “its repeated violations of the Chemical Weapons ‌Convention and, in this instance, the Biological and Toxin Weapons Convention.”

“We are further concerned that Russia did not destroy all of its chemical weapons.”

In a separate statement, British foreign minister Yvette Cooper, who met Navalny’s widow at ​the Munich Security Conference, said that the findings were “shining a light on ​the Kremlin’s barbaric plot ⁠to silence his voice.”

-with AAP