Alexei Navalny, Russia's most famous opposition leader, was "highly likely" to have been killed in a penal colony, allies of Navalny, Kira Yarmysh and Ivan Zhdanov, said on Friday.
Yarmysh said that Navalny's lawyer, who was previously reported to be on his way to the Kharp settlement where the penal colony is located, would arrive there early on Saturday.
Navalny died on Friday after collapsing and losing consciousness at the penal colony north of the Arctic Circle where he was serving a long jail term, the Russian prison service said. Navalny, 47, rose to prominence more than a decade ago by lampooning President Vladimir Putin and the Russian elite whom he accused of vast corruption, avarice and opulence.
The Federal Penitentiary Service of the Yamalo-Nenets Autonomous District said in a statement that Navalny "felt unwell" after a walk at the IK-3 penal colony in Kharp, about 1,900 km (1,200 miles) north east of Moscow.
He lost consciousness almost immediately, it said.
"All necessary resuscitation measures were carried out, which did not yield positive results. Doctors of the ambulance stated the death of the convict," the prison service said, adding that causes of death were being established.
Kremlin spokesman Dmitry Peskov said on Friday that Russia's penitentiary service was making all checks regarding the death of jailed opposition leader Navalny, but that he had no information about the matter.
Russian president Vladimir Putin has been told about Navalny's death, the spokesman added. Putin, who is running for re-election in a month, was shown on a television clip visiting a factory in the Urals.
Russian President Vladimir Putin and his associates will not go unpunished if the death of Alexei Navalny, as reported by Russian officials, turns out to be true, the Kremlin critic's wife, Yulia, said on Friday.
Yulia Navalny called upon the international community to come together and fight against the "horrific regime" in Russia, in a statement at the Munich Security Conference, speaking in Russian via an interpreter.
There is "almost no hope" that Russian opposition leader Alexei Navalny is alive, Navalny's spokeswoman Kira Yarmysh said Friday during a live Youtube broadcast.
Prison authorities said earlier that President Vladimir Putin's most formidable domestic opponent fell unconscious and died after a walk at the "Polar Wolf" Arctic penal colony where he was serving a three-decade sentence.
Navalny's wife, Yulia, told the Munich Security Conference she could not be sure her husband was dead because "Putin and his government... lie incessantly."
Navalny's press secretary: 'no confirmation of Navalny's death'
Navalny's mother was quoted by Russian newspaper Novaya Gazeta as saying that her son had been "alive, healthy and happy" when she last saw him on Feb 12.
Novaya Gazeta reported that Lyudmila Navalnaya wrote in a Facebook post on Friday: "I don't want to hear any condolences. We saw him in prison on the (Feb) 12, in a meeting. He was alive, healthy and happy."
Supporters of Navalny said they could not confirm he was dead, but that if he was then they believed he had been killed.
Navalny's team cannot confirm his death, his former deputy Leonid Volkov said on X on Friday.
"Russian authorities publish a confession that they killed Alexei Navalny in prison. We do not have any way to confirm it or to prove this isn't true," Volkov wrote.
Navalny's lawyer was travelling to the site of the prison where he had been serving his sentence, Volkov added.
He further noted that if it were true that he is dead, then Russian President Vladimir Putin killed him.
Volkov wrote on X: "We have no basis to believe state propaganda. If it's true, then it's not 'Navalny died', but only that 'Putin killed him'. But I don't believe them for a second."
The press secretary of jailed Russian opposition leader Navalny said on the X social media platform on Friday that she was unable to confirm his death.
Kira Yarmysh said that Navalny's lawyer was travelling to the site of the prison where he had been serving his sentence.
Russia's Investigative Committee has launched a procedural probe into the death of opposition leader Alexei Navalny in a penal colony, the Investigative Committee said on Friday.
Blinken says Navalny death underscores 'weakness and rot' of Putin's system
US Secretary of State Antony Blinken said on Friday that reports of Russian opposition leader Alexei Navalny's death in prison, if true, underscore what he described as the "weakness and rot" of the system President Vladimir Putin built.
"First and foremost, if these reports are accurate, our hearts go out to his wife and his family," Blinken said in Munich.
"Beyond that, his death in a Russian prison and the fixation and fear of one man only underscores the weakness and rot at the heart of the system that Putin has built. Russia is responsible for this," Blinken added.
"We'll be talking to the many other countries concerned about Alexei Navalny, especially if these reports bear out to be true," Blinken said.
US Vice President Harris on Navalny death: 'Russia is responsible'
US Vice President Kamala Harris said the death of Russian opposition politician Alexei Navalny in an Arctic penal colony on Friday, if confirmed, would be a further sign of the brutality of Russian President Vladimir Putin.
"Let us be clear, Russia is responsible," she said, adding that it would be "a further sign of Putin's brutality" of the death is confirmed.
Other reactions from international officials
The EU will do whatever it can to hold Russia accountable for the death of opposition leader Alexei Navalny, EU Commission President Ursula von der Leyen and Vice President Josep Borrell said on Friday.
"He was slowly murdered by President Putin and his regime, who fear nothing more than dissent from their own people," von der Leyen and Borrell said.
"We will spare no efforts to hold the Russian political leadership and authorities to account."
The EU commission leaders demanded Russia established all facts around Navalny's death and "immediately release all other political prisoners."
Navalny has paid with his life for his 'resistance to a system of oppression', French Foreign Minister Stephane Sejourne said on Friday in comments on the death of the famous Russian political activist.
"His death in a penal colony reminds us of the reality of Vladimir Putin's regime", said Sejourne.
Latvian President Edgars Rinkevics said on X on Friday that Navalny was "brutally murdered by the Kremlin."
"Whatever your thoughts about Alexei Navalny as the politician, he was just brutally murdered by the Kremlin. That's a fact and that is something one should know about the true nature of Russia's current regime. My condolences to the family and friends," he wrote.
Swedish Foreign Minister Tobias Billström said on X. "Dreadful news about Alexei Navalny... If the report about his death in Russian prison is true it represents another terrible crime by Putin’s regime. The ruthlessness against Navalny shows again why it is necessary to continue to fight against authoritarianism."
British Prime Minister Rishi Sunak said Navalny's death was terrible, and paid tribute to the Russian opposition leader.
"This is terrible news. As the fiercest advocate for Russian democracy, Alexei Navalny demonstrated incredible courage throughout his life," Sunak said in a post on X.
"My thoughts are with his wife and the people of Russia, for whom this is a huge tragedy."
EU Council President Charles Michel said, The European Union holds Russia responsible for the death of jailed opposition leader Alexei Navalny,
"Alexei Navalny fought for the values of freedom and democracy," Michel said in a post on X.
"For his ideals, he made the ultimate sacrifice. The EU holds the Russian regime solely responsible for this tragic death."
Alexei Navalny appears to have paid for his bravery with his life, German Chancellor Olaf Scholz said in a social media post on Friday, linking the death of the prominent Kremlin critic to the Russian political apparatus.
"He stood up for democracy and freedom in Russia - and apparently paid for his courage with his life," Scholz wrote on X, adding that the news showed "what kind of regime is in power in Moscow."
Russian Foreign Ministry responds
Russian Foreign Ministry spokeswoman Maria Zakharova said on Friday that what she called Western accusations about the death of Navalny were "self-revealing".
In a statement posted on the messenger app Telegram, Zakharova said that forensic results on Navalny's death were still unavailable but that the West had already reached its own conclusions.
Zakharova did not clarify which accusations she was referring to.
A voluntary return to Russia
Navalny earned admiration from Russia's disparate opposition for voluntarily returning to Russia in 2021 from Germany, where he had been treated for what Western laboratory tests showed was an attempt to poison him with a nerve agent.
Navalny said at the time that he was poisoned in Siberia in August 2020. The Kremlin denied trying to kill him and said there was no evidence he was poisoned with a nerve agent.
In an interview in Moscow in 2011, Navalny was asked by Reuters if he was afraid of challenging Putin's system.
"That's the difference between me and you: you are afraid and I am not afraid," he said. "I realize there is danger, but why should I be afraid?"