Russian opposition leader Alexei Navalny was killed using a poison developed from a dart frog toxin, the UK and European allies have said, BBC reported. 

Two years on from the death of Navalny at a Siberian penal colony, Britain and its allies have blamed the Kremlin following analysis of material samples found on his body.

Speaking from the Munich Security Conference, Foreign Secretary Yvette Cooper said "only the Russian government had the means, motive and opportunity" to use the poison while Navalny was imprisoned in Russia, according to BBC.