Before Saturday’s announcement, Navalny’s wife Yulia Navalnaya had consistently argued that her husband was killed by poisoning while serving a prison sentence in an Arctic penal colony in 2024.
In September last year, Navalnaya said analysis of smuggled biological samples carried out by laboratories in two countries showed that her husband had been “murdered”.
She did not provide details on the poison allegedly used, on the samples or on the analysis – but challenged the two laboratories to publish their results.
Reacting to the announcement, Navalnaya said: “I was certain from the first day that my husband had been poisoned, but now there is proof.
“I am grateful to the European states for the meticulous work they carried out over two years and for uncovering the truth,” she added.
The Kremlin has not commented on the allegations.
Russian President Vladimir Putin, who studiously avoided naming Navalny while he was alive, briefly referred to him a month after his death by stating that a person passing was “always a sad event”.
At the time of his death, Navalny had been in jail for three years on trumped-up charges and had recently been transferred to the Arctic Circle penal colony.
According to Russian accounts, the 47-year-old took a short walk at his Siberian penal colony, said he felt unwell, then collapsed and never regained consciousness.
Speaking to BBC Russian, toxicology expert Jill Johnson said epibatidine was “200 times more potent than morphine”.
By acting on receptors in the central nervous system, it can cause “muscle twitching and paralysis, seizures, slow heart rate, respiratory failure and finally death,” she said.
The extremely rare neurotoxin is only found in one wild frog species in tiny quantities, and only when the frog eats a specific diet, Johnson said, describing it as an “incredibly rare way to poison a person”.
She said: “Finding the wild frog in the correct location that is eating the specific diet to create the correct alkaloids is almost impossible…almost.”