Russian opposition leader Alexei Navalny was killed using a poison developed from a dart frog toxin, the UK and European allies have said.

Two years on from the death of Navalny at a Siberian penal colony, Britain and its allies have blamed the Kremlin following analysis of material samples found on his body.

There is no innocent explanation for the toxin, called epibatidine, being found in samples taken from Navalny's body, the UK Foreign Office stated.

Speaking from the Munich Security Conference, Foreign Secretary Yvette Cooper remarked, Only the Russian government had the means, motive and opportunity to deploy this lethal toxin against Alexei Navalny during his imprisonment in Russia.

While Cooper announced the findings, a joint statement was issued by the UK, Sweden, France, Germany, and the Netherlands.

Cooper met with Navalny's widow Yulia Navalnaya at the conference this weekend. Russia saw Navalny as a threat, she said. By using this form of poison, the Russian state demonstrated the despicable tools it has at its disposal and the overwhelming fear it has of political opposition.

The statement further emphasized, 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.

Epibatidine is naturally found in dart frogs in South America and is not produced in captivity or found commonly in Russia.

The Foreign Office has informed the Organisation on the Prohibition of Chemical Weapons of Russia's alleged breach of the Chemical Weapons Convention.

UK Prime Minister Sir Keir Starmer praised Navalny’s huge courage, asserting that his determination left an enduring legacy. Foreign Minister Jean-Noël Barrot added that Navalny was murdered for his fight for democracy in Russia.

Navalny died in jail on February 16, 2024, at the age of 47, heavily influencing Russian politics as a vocal anti-corruption campaigner. He was also previously poisoned with a Novichok nerve agent in 2020 and treated in Germany before being arrested upon returning to Russia.

His wife, Yulia Navalnaya, has continuously claimed since his death that her husband was murdered, echoing her frustration and challenge to labs conducting tests. Following the recent announcement, she expressed gratitude for the efforts of European nations that helped bring the truth to light, declaring, I was certain from the first day that my husband had been poisoned, but now there is proof.