Russia has demanded 'concrete' evidence that it poisoned opposition leader Alexei Navalny with epibatidine, a rare toxin from poison dart frogs. On Saturday, Britain, France, Germany, Sweden, and the Netherlands said tests on Navalny’s body confirmed the presence of this toxin, which does not occur naturally in Russia. They claimed Moscow had the "means, motive and opportunity" to poison Navalny. Russian Foreign Ministry spokeswoman Maria Zakharova dismissed the accusations as "highly likely" but without specifics. She said, "We demand they hand over concrete data on this issue." The Kremlin firmly denied the European claims. Meanwhile, Navalny’s widow, Yulia Navalnaya, attending the Munich security conference, said there is now "proof" her husband was poisoned. She wrote on social media, "[Vladimir] Putin killed Alexei with a chemical weapon," calling Putin a "murderer" who "must be held accountable." The announcement came as the world marked two years since Navalny’s death on February 16, 2024, in a harsh Arctic prison camp during a 19-year sentence many see as politically driven. At 47, his death left Russia’s opposition weakened and divided. His mother, Lyudmila Navalnaya, and mother-in-law laid flowers at his grave in Moscow’s Borisovsky Cemetery. Lyudmila said, "We knew that our son did not simply die in prison. He was murdered." Moscow denies involvement, stating Navalny fell ill after a walk. Kremlin spokespeople called the poisoning claims "biased and unfounded" and rejected them outright. Navalny had survived an earlier poisoning attack with a nerve agent in 2020, which he blamed on the Kremlin. After recovering in Germany, he returned to Russia to face immediate arrest and imprisonment. His allies continue their fight mainly from exile, though they face prison sentences and official bans in Russia. The opposition remains fragmented, trading accusations. Recently, the Council of Europe’s PACE set up a new platform to give Russian opposition a voice in Europe. However, some opposition groups, including Navalny’s anti-corruption team, are not part of it. PACE’s Russian members stated Navalny’s death was "an inevitable link in a chain of systemic crimes by the Kremlin regime." They added, "Alexei Navalny gave his life for a free Russia. We are obliged to ensure that his death was not in vain."