Russian opposition leader Alexei Navalny was allegedly killed using a poison derived from dart frog toxin, according to UK and European allies. The Kremlin has been blamed for his death, with Foreign Secretary Yvette Cooper stating that only the Russian government had the means to use the poison while Navalny was imprisoned. The toxin, epibatidine, is not found naturally in Russia and its presence in Navalny's body raises serious questions. Navalny's widow, Yulia Navalnaya, expressed gratitude for the findings, while Russian officials dismissed the claims as an information campaign.