A frog from southern Ecuador and northern Peru is at the center of the case of the Russian opposition figure Navalny

Quito.- The death of Russian opposition figure Alexei Navalny, which occurred in 2024, returned to the international debate following accusations from several European governments that he was poisoned with epibatidine, a toxin from a frog that lives between southwestern Ecuador and northern Peru.

The governments of the United Kingdom, Sweden, France, Germany, and the Netherlands stated in a statement that they reached the conclusion about the poisoning based on samples taken from Navalny's body, which conclusively confirmed the presence of epibatidine, according to the European nations. However, the Kremlin has rejected such accusations. Santiago Ron, doctor in evolutionary biology and member of the World Academy of Sciences, told EFE this Monday that the frog belongs to the genus Epipedobates anthonyi, part of the family of poison dart frogs.

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They are diurnal and many of the species within this group are aposematic, that is, they have bright colors, which can range from brown to red, that warn their predators that they are dangerous, he explained. He asserted that the frog is not in humid forests, as has been mentioned, but rather, frequently, in somewhat disturbed areas, which mix native vegetation and crops. They are always near water sources, streams, because their reproduction depends on that.

Is a Deadly Poison on the Skin?

Amphibian curator at the Vertebrate Zoology Museum of the Pontifical Catholic University of Ecuador, Ron emphasized that these frogs - about two centimeters - do not directly produce the toxin, but obtain it from their diet of mites and ants. "They sequester those toxins present in the diet and pass them to the skin, and in that way they protect themselves from their predators," he assured.

"If you touch the frog and then your eyes or mouth, you will feel pain or burning, but you will not die. The amount of venom each little frog has is very low," he said, pointing out that the venom does not pass through the skin, so for humans they are "practically harmless."

According to the expert, between 100 and 200 specimens would be needed to gather a lethal dose. Furthermore, there is already an antidote that neutralizes its effect because the chemical basis of epibatidine and how it affects the nervous system are already known.

Created in the laboratory

The compound was isolated in the 70s by researchers from the American Museum of Natural History during an expedition in Ecuador. The venom is no longer necessary to extract from the frogs, "because it can now be synthesized in the laboratory," explained Ron. Russia has always claimed that Navalny died of natural causes in prison in February 2024, but the aforementioned five European countries maintain that, given the toxicity of epibatidine and the reported symptoms, poisoning is very likely to have been the cause of his death.

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«Only the Russian government had the means, motive, and opportunity to use this lethal toxin against Alexei Navalny during his imprisonment in Russia. Today, alongside his widow, the United Kingdom sheds light on the Kremlin's barbaric plot to silence his voice,» assured Yvette Cooper, British Foreign Secretary, on Saturday. Yulia Navalnaya denounced her husband's poisoning in September 2025, although the foreign laboratories involved did not publish the final results at the time.