The Kremlin said Monday that it "strongly rejected" an assessment by five European countries that Russian opposition leader Alexei Navalny died from poisoning two years ago, as his supporters marked the anniversary of his death in prison.
Navalny, a charismatic anti-corruption campaigner who rallied hundreds of thousands to the streets in protest at the Russian leadership, was Russian President Vladimir Putin's fiercest domestic opponent for years.
He 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, said AFP.
Britain, Sweden, France, Germany and the Netherlands issued a joint statement on Saturday saying they believed he had been poisoned with epibatidine -- a toxin found in poison dart frogs -- and that the Russian state had the "means, motive and opportunity" to administer it.
"We naturally do not accept such accusations. We disagree with them. We consider them biased and baseless," Kremlin spokesman Dmitry Peskov told reporters, including AFP, during a daily briefing call.
"In fact, we strongly reject them," he added.
Dozens of people visited his grave in Moscow early Monday, among them foreign diplomats, according to an AFP reporter at the scene.
Some of those who attended wore masks or scarves over their faces.
Russian authorities designated Navalny and his organization "extremist" before his death, and anyone who mentions him or his exiled anti-corruption foundation are liable for prosecution.
Navalny, a Yale-educated lawyer, was the most widely known Russian opposition figure and galvanized thousands of young people to protest against Putin.
He had already survived a suspected poisoning with the Novichok nerve agent in 2020.
- Ecuadoran dart frog -
Navalny's mother Lyudmila told reporters she felt vindicated by the European statement and called for those responsible to be held accountable.
"This confirms what we knew from the very beginning. We knew that our son did not simply die in prison, he was murdered," she said outside the cemetery where he was buried in Moscow.
"I think it will take some time, but we will find out who did it. Of course, we want this to happen in our country, and we want justice to prevail," she added.
Navalny's widow, Yulia Navalnya, said on Saturday it was now "science proven" that her husband had been murdered.
She had previously said in September that laboratory analysis of smuggled biological samples found that her husband was poisoned.
Epibatidine, found in the Ecuadoran dart frog, causes muscle paralysis and eventual asphyxiation.
Experts have said the toxin can also be produced synthetically, instead of extracting it directly from the frog itself.
The European statement did not say how it was administered or by whom.
Britain's foreign office said the poison is not found naturally in Russia and that "only the Russian state had the means, motive and opportunity to deploy this lethal toxin."
Russia's prison service said he died after going for a walk and falling ill.
Since Navalny's death, Russia's opposition has remained largely exiled and fragmented.
Navalny's widow Yulia vowed to take the mantle of Russia's opposition in the wake of his death but has struggled to galvanize widespread support.
Inside Russia, Moscow has intensified a crackdown on anybody who had links with the late opposition leader.
In addition to targeting his allies and backers, photographers who covered his court hearings and lawyers who represented him at trial have been sentenced to lengthy prison terms.
