How Did Alexei Navalny Die? UK Says Russia Used Dart Frog Toxin on Opposition Leader

Alexei Navalny, Russia's opposition leader who gained recognition worldwide for his anti-corruption campaign, was revealed to have been killed using a dart frog toxin, according to the UK and European allies. Navalny's cause of death revelation comes two years after his sudden death whilst in jail in 2024.

Foreign Secretary Yvette Cooper announced the findings during the Munich Security Conference, after an analysis was conducted on material samples found on Navalny's body. A joint statement was released by the governments of the UK, Sweden, France, Germany, and the Netherlands. Cooper said that no one other than the Russian government could administer the poison on Navalny whilst he was imprisoned in a penal colony in Siberia. Moscow, according to the Tass news agency, dismissed the findings as 'an information campaign'. However, Cooper said there is no other explanation for the presence of the dart frog toxin, also called epibatidine, being found on Navalny.

What the Governments Say

Cooper had met with Navalny's widow, Yulia Navalnaya whilst at the conference, saying that Navalny posed a threat to Russia, which would explain why he was poisoned. '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,' said Cooper.

In the joint statement, the governments of the five European countries said they hold Moscow responsible for Navalny's sudden death. '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,' the statement said. '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,' the statement added.

The British Foreign Office has already informed the Organisation on the Prohibition of Chemical Weapons of Moscow's alleged breach of the Chemical Weapons Convention. Prime Minister Keir Starmer said Navalny was known for his 'huge courage' and 'his determination to expose the truth has left an enduring legacy'.

'I am doing whatever it takes to defend our people, our values, and our way of life from the threat of Russia and Putin's murderous intent,' said Starmer.

A Man Being Targeted

Navalny's outspoken anti-corruption stance as opposition leader has been known to draw the ire of the Kremlin. In 2020, he was poisoned with a Novichok nerve agent and went to Germany for treatment, only to get arrested at the airport when he returned to Russia. Navalny would ultimately pass away on 16 February 2024 at 47.

Navalnaya, prior to Cooper's announcement, has long argued that her husband was deliberately poisoned whilst he was serving his sentence at the Arctic penal colony. In September 2025, she said that the analysis of smuggled biological samples done by laboratories in two countries seemed to make clear that her husband was poisoned.

'I was certain from the first day that my husband had been poisoned, but now there is proof,' said Navalnaya. 'I am grateful to the European states for the meticulous work they carried out over two years and for uncovering the truth.'