Navalny's precise location had been unknown after his legal team said last week that he had been moved from the nearby Kolchugino jail and that they had not been told where he was being taken.
Navalny, 44, one of President Vladimir Putin's most prominent critics, was jailed earlier this year for parole violations in a decision that the West has condemned as politically motivated.
His Instagram account said he was being held in a heightened security section of the prison camp.
