Alexei Navalny, likely moved to black site, faces fate similar to Putin's dead enemies

Alexei Navalny, the imprisoned Russian opposition leader, has been taken from the correctional colony where he was serving his term, and his whereabouts are unknown, as per his spokesperson.

Kira Yarmysh said on social media that Melekhovo colony officials informed him that Alexei Navalny was no longer registered there.

The White House stated that the revelations have "deeply concerned" it.

After his prison term was extended, Navalny's allies expected him to be sent to a tougher regime jail.

His disappearance is said to be connected to recent election declarations.

Russian President Vladimir Putin announced his decision to run for re-election in March of next year on Friday.

Navalny was found guilty in August of forming and sponsoring an extremist movement, which he denies, and was sentenced to a further 19 years in prison.

He had already received a nine-year term for parole breaches, fraud, and contempt of court. All of the accusations levelled against him are commonly seen as politically motivated.

He was told that he would have to continue his detention in a "special regime colony," a sort of jail intended for dangerous criminals, repeat offenders, and those sentenced to life in prison.

Navalny's acquaintances stated earlier on Monday that they had not heard from him in six days.

He had missed many recent court hearings, which he had previously attended by video connection. Prison officials blamed the absences on technological difficulties at the colony.