The EU said the people were involved with the development of chemical weapons, particularly epibatidine, that were found in samples taken from the activist's body after his death. The toxin is found in poison dart frogs in South America and not found naturally in Russia.Russia has demanded that European countries who accuse Moscow of poisoning Navalny to provide concrete data to support their allegations.People listed under the sanctions programme are subject to an asset freeze and travel ban to the EU.