Alexey Navalny is dead: Putin's political nemesis died suddenly in prison, Russian officials say

• The Russian opposition politician Alexey Navalny has died in prison.
• The 47-year-old was being held in an Arctic penal colony with harsh conditions.

Alexey Navalny, Vladimir Putin's political nemesis, died suddenly in prison at the age of 47, officials said.

Russia's Federal Prison Service said Navalny felt unwell after taking a walk and almost immediately lost consciousness.

Medics were called and tried to revive him, but he was quickly pronounced dead, a statement said. It did not explain further.

Navalny was imprisoned in a detention facility about 40 miles north of the Arctic Circle, where he was serving a 19-year sentence which many saw as punishment for his opposition to the Russian president.

Hours after his death, the Russian SOTA social-media channel shared what it said was footage of Navalny in court this week. He appeared to be healthy and smiling.

For years, Navalny had been Putin's most formidable domestic critic, criticizing what he characterized as the corruption and ineptitude of the Russian president and his inner circle. He organized large anti-Kremlin protests that were suppressed by Russian authorities.

Kira Yarmysh, Navalny's spokesperson, said on X that Navalny's death was not confirmed. "Alexey's lawyer is currently on his way to Kharp. As soon as we have some information, we will report on it," she said.

Navalny's chief of staff, Leonid Volkov, posted on X: "Russian authorities publish a confession that they killed Alexey Navalny in prison. We do not have any way to confirm it or to prove this isn't true."

The European Union said that it held Russia responsible for the death of the Russian opposition politician.

"Alexei Navalny fought for the values of freedom and democracy. For his ideals, he made the ultimate sacrifice," European Council President Charles Michel posted on X. "The EU holds the Russian regime for sole responsible for this tragic death."

US President Joe Biden in 2021 said that Russia would suffer "devastating" consequences if Navalny were to die in jail.

Kremlin spokesman Dmitry Peskov told Russian media that Putin had been informed of Navalny's death but had no further information.

Pro-Kremlin channel RT, citing an anonymous source, said Navalny died from a "blood clot".

However, Alexander Polupanov, a doctor who treated Navalny in 2020, cast doubt on these claims in comments to the BBC, saying that an autopsy would be necessary to establish this as the cause of death and there hadn't been time to carry one out.

Navalny's sudden death brings with it an end to any significant political opposition to Putin that still existed in Russia.

In the 2020 Oscar-winning documentary about his life, "Navalny," he appeared to anticipate his death.

"If they decide to kill me it means that we are incredibly strong. We need to utilize this power, to not give up, to recognize that we are this huge power that is being oppressed by these bad dudes," Navalny said. "We don't realize how strong we actually are."

In 2020, Navalny became ill on board a flight to Moscow from Tomsk, Siberia. He was taken to Germany, where medical experts said he was poisoned with a chemical nerve agent from the Novichok family.

At the time, Russia denied that Putin was behind the poisoning and refused to open a criminal investigation — a move that the European Court of Human Rights ruled violated Navalny's rights.

Navalny recovered in Germany for several months. He voluntarily returned to Russia in January 2021, despite the strong likelihood that he would be punished.

"The question 'to return or not' never stood before me," he said in an Instagram post on January 2021. "Mainly because I never left. I ended up in Germany, having arrived in an intensive care box, for one reason: they tried to kill me."

He was arrested at the airport as soon as he landed.