Aleksei A. Navalny, Russia’s most prominent opposition leader, who is currently serving a 19-year sentence in a Russian penal colony, missed another court date on Monday as his allies expressed concern at not having heard from him for more than five days.
Mr. Navalny, 47, a fierce critic of President Vladimir V. Putin over the past decade and a frequent target of Kremlin attacks, was scheduled to appear in a district court in the city of Kovrov, east of Moscow, via a video link.
But the screen in the courtroom remained dark, and his allies said that they had not been in touch with Mr. Navalny since Tuesday, Kira Yarmysh, his spokeswoman, said on Monday.
According to Ms. Yarmysh, the authorities in Mr. Navalny’s penal colony have been blaming problems with electricity for his absence. But given the harsh nature of his imprisonment, serving one sentence after another in a “punishment” cell, his allies said they were convinced that there must have been other factors at play.
“They are just mocking us,” Ms. Yarmysh said on Monday in a post on X, formerly known as Twitter.
Later on Monday, hints emerged that Mr. Navalny could be getting transferred to another prison. Ms. Yarmysh said that an official from his current penal colony, in the Vladimir region, east of Moscow, had told Mr. Navalny’s lawyer that such a prisoner was no longer listed there.
As part of his last sentence, delivered by a Russian court in August, Mr. Navalny was to be transferred to a different kind of penal colony, one of Russia’s strictest, known as “special regime.” Such prisons are scattered across the country. But officials at the nearest one, also in the Vladimir region, told lawyers that Mr. Navalny was not there either.
“We still don’t know where Alexey is,” Ms. Yarmysh posted on X, using an alternative spelling of Mr. Navalny’s first name.
Last Wednesday, Mr. Navalny’s lawyer could not get access to him in the penal colony after waiting in front of the facility for seven hours. There was no explanation given, Ms. Yarmysh posted, adding that it was the first time that had happened.
The next day, Mr. Navalny missed a court hearing and his lawyers were again not allowed to see him, Ms. Yarmysh said. The same situation happened again on Friday, she said.
“The fact that we can’t find Alexey is particularly worrying because he fell ill in his cell last week: he got dizzy and laid down on the floor,” Ms. Yarmysh said on Friday in a post on X. “Before that, there were at least occasional letters from him, albeit censored ones, but there have been no letters all week.”
While in prison, Mr. Navalny has still managed to retain a significant presence in Russia’s political opposition by publishing statements and delivering speeches in court. Last week, Mr. Navalny began a campaign urging his followers to vote for any other candidate than Mr. Putin in the next presidential election, scheduled for March.
Mr. Navalny has been in custody in Russia since his detention in January 2021 in a Moscow airport, where he arrived after spending months in Germany, recovering from a poisoning by a nerve agent. Mr. Navalny blamed the Kremlin for the poisoning, but the Russian authorities denied their involvement.
Subsequently, the Russian authorities have brought forth a multitude of new charges against him. According to Ms. Yarmysh, Mr. Navalny is currently a defendant in 14 criminal cases and faces a potential sentence of up to 35 years in prison.