Was Navalny poisoning by frog toxin meant to send a message?

Yvette Cooper may think so, and use of epibatidine may seem exotic, but experts say situation is more ambiguous

It was a very particular choice of weapon, but experts say it remains unclear whether the dart frog toxin used to kill the Russian opposition leader Alexei Navalny was intended to convey a message.

Known as epibatidine, the poison is produced by wild dart frogs native to parts of South America - meaning Navalny could not have accidentally taken the poison.