India, Feb. 17 -- Days after European leaders accused Russia of 'poisoning' opposition leader Alexei Navalny in prison using a 'rare toxin', South American dart frog experts on Monday reportedly said that the particular toxin was likely a lab-produced replica, rather than sourced from the wild.

Neurotoxin epibatidine is believed to be carried by a number of South American dart frog species in the forests of Ecuador and Peru, reported news agency AFP.

Foreign ministries of the UK, France, Germany, Sweden and the Netherlands alleged that opposition leader and a strong critic of President Vladimir Putin was poisoned by Russia with the rare and lethal toxin found in the skin of poison dart frogs.

Alexei Navalny passed away in an Arctic pri...