Russia poisoned opposition leader Alexei Navalny with a deadly toxin found in Ecuadorian dart frogs while he was in prison, the United Kingdom and European allies have said.

Five European countries on Saturday accused Russia of ‘poisoning’ opposition leader Alexei Navalny in prison using a ‘rare toxin’.

In a joint statement, Britain, France, Germany, Sweden and the Netherlands on Saturday said analyses of samples from Navalny's body "conclusively" confirmed the presence of epibatidine, a toxin found ...