Jailed Russian opposition politician Alexei Navalny has been moved to a penal colony in an Arctic region of northern Russia, his spokeswoman says after supporters lost touch with him for more than two weeks.
Navalny was tracked down to the IK-3 penal colony in Kharp in the Yamal-Nenets region, about 1900km northeast of Moscow, spokeswoman Kira Yarmysh said.
Navalny's lawyer managed to see him on Monday, Yarmysh said.
"Alexei is alright," Yarmysh said.
Navalny's allies, who had been preparing for his expected transfer to a "special regime" colony, the harshest grade in Russia's prison system, said he has not been seen by his lawyers since December 6 and raised the alarm about his fate.
"Many thanks to our supporters, activists, journalists and the media who are concerned about Alexei's fate and who do not get tired of writing about the situation," Navalny lawyer Ivan Zhdanov said.
Navalny's new home, known as "the Polar Wolf" colony, is considered to be one of the toughest prisons in Russia.
Most prisoners there have been convicted of grave crimes.
Winters are harsh - and temperatures are due to drop to about minus 28C there over the next week.
About 60km north of the Arctic Circle, the prison was founded in the 1960s as part of what was once the GULAG system of forced Soviet labour camps, according to the Moskovsky Komsomolets newspaper.
"The conditions there are harsh, with a special regime in the permafrost," said Leonid Volkov, an aide to Navalny.
He said it was difficult to communicate with prisoners held at the remote site.
Lawyer Zhdanov said supporters of Navalny had sent 618 requests for information about his location and suggested that the Russian authorities wanted to isolate Navalny ahead of the March presidential election.
Navalny, who had been held at a penal colony 235km east of Moscow, says he has been imprisoned because he is viewed as a threat by the Russian political elite. As a prisoner, he is unable to run in the election.
He denies all the charges he has been convicted of and casts Russia's judicial system as deeply corrupt.
Russia says he is a convicted criminal.
Navalny, now 47, earned admiration from Russia's disparate opposition for voluntarily returning to Russia in 2021 from Germany, where he had been treated for what European laboratory tests indicated was an attempt to poison him with a nerve agent.
Navalny says 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.
His supporters cast him as a future leader of Russia who will one day walk free from jail to lead his country, although it is unclear how much popular support Navalny has inside Russia.
The authorities view him and his supporters as extremists with links to the CIA intelligence agency who they say is seeking to destabilise Russia.
They have outlawed his movement, forcing many of his followers to flee abroad.
Last month Navalny lamented the terrible state of inmates' teeth in Russian prison.
"Poor nutrition, a lack of solid food, lots of sweet stuff (the most affordable food), a lot of strong tea, smoking and a complete absence of dental care do them in," he said at the time.