European capitals alleged Saturday that Navalny – a fierce critic of President Vladimir Putin – was killed by the neurotoxin epibatidine, found in “poison dart frogs in South America.”
A number of South American dart frog species are believed to carry the toxin, with the most likely suspect found in the jungles of Ecuador and Peru.
The frogs themselves are easy enough to come by, both legally with permits and illegally for a few dollars.
“It’s not difficult to find them at any market,” said Andrea Teran, of Ecuador’s Jambatu Center for Amphibian Research and Conservation.
In the last ten years, more than 800 of the suspected species – Epipedobates anthonyi, also known as Anthony’s poison arrow frog – have been legally exported from Ecuador, according to CITES permit data.
Still, despite images of spies roaming the jungles of Ecuador or the black market, experts said it is more likely that the toxin was a synthetic copy rather than the real thing.
“It’s easier to buy the toxin or obtain it from labs that produce it,” said Teran.
Wild diet needed
The quantity of toxin needed and the logistics involved in harvesting make synthetics a much easier option.
A conservation centre called Tesoros de Colombia holds permits to trade this and related frogs as pets and for scientific and pharmaceutical use.
Ivan Lozano, the center’s director, told AFP an “enormous number of frogs” – each about two to three centimetres long, would be needed to produce a lethal dose for a human.
He said he believes it is “impossible” to gather that many to make a deadly poison.
Only a “synthetic version” made in a laboratory could kill a person, he said.
There is also a question of timing.
The frog’s toxins come from its insect diet in the wild, and are quickly lost in captivity, according to Devin Edmonds of the University of Illinois.
“The alkaloids in the skin of captive-bred frogs differ a lot from wild frogs,” he told AFP.
“In captivity, they are fed fruit flies so they aren’t poisonous,” he said.
“Wild frogs in captivity will lose their toxicity after a few months of eating flies”.
Navalny died in an Arctic prison colony in February 2024 while serving a 19-year sentence for “extremism,” a charge that he and his supporters say was punishment for his opposition work.
Britain, Sweden, France, Germany and the Netherlands issued a joint statement on Saturday saying they believed he had been poisoned with epibatidine.
“We naturally do not accept such accusations. We disagree with them. We consider them biased and baseless,” Kremlin spokesman Dmitry Peskov told reporters.
Russia and the Soviet Union have a long history of developing, researching and allegedly using toxins – from ricin to Novichok – against political foes.