European countries have stated that the cause of Alexei Navalny's death could have been poisoning by a rare toxin — epibatidine, a substance of natural origin that is secreted by the skin of South American poison dart frogs. According to the claims of the United Kingdom, Sweden, France, Germany, and the Netherlands, traces of this poison were found by several independent laboratories when analyzing samples of the deceased politician's biological materials. It is reported that the family managed to take these samples out of Russia for research purposes.
Russian opposition leader Alexei Navalny, considered the main political opponent of President Vladimir Putin, died in a penal colony two years ago after returning to Russia. Earlier, in 2020, there was an attempt to poison him with a substance from the 'Novichok' group, after which he received treatment abroad. Russian authorities denied their involvement in the poisoning and later stated that Navalny died of natural causes in custody.
The British Foreign Office stated in a published statement that five European countries concluded: the politician was poisoned with a deadly substance. Laboratory studies confirmed the presence of epibatidine in his biological materials. The British side emphasized that this toxin occurs naturally in South America and is not characteristic of nature in Russia, which, in their opinion, strengthens suspicions of its deliberate use.
According to London, the high toxicity of epibatidine and the described symptoms make the poisoning version the most likely. The statement also notes that the death occurred during imprisonment, which means that Russian authorities allegedly had opportunities to use such a substance. Five countries notified the Organization for the Prohibition of Chemical Weapons about the alleged violation of the Chemical Weapons Convention by Russia.
The British Foreign Office added that it considers this case not as an isolated incident, reminding of the alleged use of 'Novichok' against Navalny in 2020, as well as the events in the British city of Salisbury, where Dawn Sturgess died from the same substance.
Moscow rejected the accusations. The official representative of the Russian Foreign Ministry, Maria Zakharova, stated in a comment to TASS that conclusions could only be made after the publication of specific test results and formulas of substances. According to her, without this data, the statements of European countries appear to be an information campaign aimed at distracting attention from the internal problems of the West.
The politician's widow, Yulia Navalnaya, on the contrary, thanked the European countries for the investigation and stated that from the very beginning she was sure of her husband's poisoning. According to her, the results obtained only confirmed this version. Back in September 2025, she reported that biological material samples had been smuggled out of Russia and that two laboratories independently concluded poisoning, but the details of the studies were not disclosed at that time.
Epibatidine is an extremely potent neurotoxin, first discovered in 1974; its chemical structure was finally established only in 1992. Scientists studied the substance for a long time due to its strong analgesic effect, which does not cause addiction, unlike opioids. Nevertheless, it has not been possible to develop a safe drug based on it: even small doses can be deadly.
Experiments on animals show that epibatidine can cause a sharp increase in blood pressure, seizures, respiratory paralysis, coma, and ultimately death. Resuscitator Alexander Polupan, who treated Navalny after the poisoning in 2020, told The Insider that the symptoms described in open sources generally correspond to the known mechanism of action of this toxin.