Allies of imprisoned opposition politician Alexei Navalny sounded the alarm on Tuesday, saying the Kremlin critic has been moved from the prison where he was serving his time and they do not know where he is now.

His attorneys were told Navalny was moved to another prison, but in Russia prison transfers sometimes take days and are shrouded in secrecy.

“All this time that we don’t know where Alexei is. He is left alone with the system that has already once tried to kill him,” Navalny’s spokesman Kira Yarmysh said on social media.

Navalny’s closest ally, Leonid Volkov, said on Telegram that the politician’s lawyer went to visit him in prison on Tuesday and was told that “there is no such convict here.”

“Where Alexei is now and which prison he is being taken to, we don’t know,” Volkov said.

Lawyer Olga Mikhaylova told Russia’s state news agency Tass that Navalny’s attorneys were told he was transferred to a maximum-security prison, “but which one, we weren’t told.”

Navalny, the most determined political foe of Russian President Vladimir Putin, was arrested in January 2021 upon returning from Germany, where he had been recuperating from nerve-agent poisoning that he blames on the Kremlin, and handed a 2½-year sentence for a parole violation.

In March, Navalny was sentenced to nine years in prison for fraud and contempt of court, charges he rejected as politically motivated and an attempt by the authorities to keep him behind bars for as long as possible.

The judge ordered the Kremlin critic to serve the new sentence in a maximum security prison. He was supposed to be transferred to one after he lost his appeal.

The new conviction followed a year-long Kremlin crackdown on Navalny’s supporters, other opposition activists and independent journalists in which authorities appear eager to stifle all dissent.

Navalny’s close associates have faced criminal charges and many have left the country, while his group’s political infrastructure — an anti-corruption foundation and a nationwide network of regional offices — has been destroyed after being labeled an extremist organization.

Until now, Navalny has been at the IK-2 penal colony in the Vladimir region, about 100 kilometers (62 miles) east of the Russian capital. The facility in the town of Pokrov stands out among Russian penitentiaries for its especially strict inmate routines, which include standing at attention for hours.

Yarmysh on Telegram cited rumors that Navalny was supposed to be transferred to IK-6, a maximum security colony in the same region, 150 kilometers east of IK-2, but noted that “neither Alexei’s attorneys nor his relatives were informed about his transfer.”

Lawyer Mikhaylova wouldn’t confirm these rumors in a phone conversation with The Associated Press, saying that all she knows is that “he was taken away in an unknown direction.”

Russia’s secrecy about prisoner transfers has come under criticism from human rights advocates.

(AP)