Putin's biggest critic is now missing from prison a week after the Russian president announced another run for office

• Russian opposition leader Alexei Navalny is now missing, his lawyers say.
• They cannot contact him, and prison authorities won't say where he is, his lawyers announced Monday.

Russian opposition leader Alexei Navalny cannot be found in the penal colony where he was carrying out his decadeslong prison sentences, lawyers said Monday.

Navalny, incarcerated in a penal colony nearly 120 miles east of Moscow, could no longer be located at two penal colonies. Navalny's lawyer said on X that authorities refused to say if or where Navalny was transported.

"Where Alexei is is still unknown," Kira Yarmysh, who represents Navalny, wrote on X.

The disappearance comes just weeks after Navalny, a vocal critic of Russian President Vladimir Putin who has been incarcerated since January 2021, fell ill and had to be put on an IV drip, his lawyer said. Following his unknown sickness, lawyers could speak to him, but contact with him has been nonexistent over the past six days.

The disappearance also comes after Putin announced on Friday his run for the presidency in 2024.

Yarmysh said Navalny's lawyers repeatedly pressed to visit him last week at the maximum security IK-6 penal colony but were denied entry. She said letters also went unanswered, and he began missing scheduled video court hearings.

Navalny is serving out a 19-year prison sentence, on top of another 11-year prison sentence related to extremism charges. He was eventually due to be transferred into a "special security" prison, the Associated Press reported.

Supporters of Navalny believe that the charges are politically motivated because of his opposition to the Kremlin leader, who has served as president for two decades. Putin has long been suspected of assassinating his critics and opponents.

A Kremlin spokesperson did not immediately respond to a request for comment.