Alexei Navalny, Russia's most important opposition leader for the past decade, has died in an Arctic prison, prison authorities have announced.
Navalny, considered President Vladimir Putin's most vocal critic, was serving a 19-year sentence on charges widely believed to be politically motivated.
He was transferred to one of Russia's toughest penal colonies late last year.
Prison authorities in the Yamalo-Nenets region said Navalny “feeled unwell” after a walk on Friday.
The newspaper said in a statement that the man “lost consciousness almost immediately,” adding that emergency medical teams were immediately called and attempts were made to resuscitate him without success.
“Emergency doctors pronounced the prisoner dead. The cause of death is still being determined.”
Navalny's lawyer Leonid Solovyov told Russian media he would not comment yet, but Navalny's close aide Leonid Volkov said of X: “Russian authorities killed Alexei Navalny in prison. “We have no way of confirming or proving that.” This is not true. ”
Within minutes of prison authorities announcing Navalny's death, the international community praised the courage of President Vladimir Putin's biggest domestic opponent.
France said he paid with his life for resisting Russia's “tyranny,” while Norway's foreign minister said Russian authorities bore grave responsibility for his death.
Putin's spokesman Dmitry Peskov said only that Navalny's death had been “reported to the president” during a visit to Chelyabinsk.
Most of the Russian president's critics have fled Russia, but Alexei Navalny returned home in January 2021 after months of treatment. In August 2020, he was poisoned with the nerve agent Novichok at the end of a trip to Siberia.
His team was able to fly him to Germany for specialist treatment, and upon his return to Moscow he was taken into custody. He never left prison again for the next 37 months.
Navalny, 47, had long sought to challenge Vladimir Putin at the polls but was barred from running in the 2018 presidential election. Next month, the Russian leader will not bow to any serious opposition.
Anti-war candidate Boris Nadezhdin has been banned from running for office after fraud was found in thousands of signatures submitted in support of his candidacy.
Navalny, who began his opposition in the form of an anti-corruption campaign, is the latest in a string of prominent Russian figures to die while challenging President Vladimir Putin's rule.
In 2015, opposition leader Boris Nemtsov was shot dead on a Moscow bridge just a stone's throw from the Kremlin, and Wagner leader Evgeny Prigozhin led a group of mercenaries in an armed revolt in August 2023. He died a few weeks later in an unknown plane crash.
But Navalny repeatedly laughed off his friends' health concerns. He was removed from a penal colony east of Moscow in December and was not seen for several weeks before reappearing in a penal colony in the Arctic town of Harup.
Navalny said he was forced to travel around Russia for 20 days and told reporters in court via video that his conditions were “much better” than in his former penal colony of Vladimir.
However, he was repeatedly punished with solitary confinement in prison. His spokeswoman Kira Yarmis said last month that he had spent more than 280 days in isolation.
Navalny was convicted of extremism last August and was not scheduled to leave prison until he was in his 70s. This was his third prison sentence, and his supporters accused the Kremlin of trying to permanently silence him.
Russian human rights activist and journalist Eva Melkacheva said on Friday that she had been placed in solitary confinement at least 27 times, which she said “could have had an impact” on his death.
In such extreme conditions, she said, under the law no one could be given isolation for more than 15 days, as doctors knew such punishment was extremely harmful to the human body.