Russian President Vladimir Putin has dismissed Aleksandr Kalashnikov as director of the Federal Penitentiary Service (FSIN), the Kremlin said in a statement, after disturbing videos of torture and rape inside a jail were leaked.
Putin replaced Kalashnikov with Arkady Gostev, a former deputy interior minister.
Kalashnikov has also been subjected to Western sanctions over the jailing of Kremlin critic Aleksei Navalny. He served as prison chief for only two years.
The reason for Kalashnikov's dismissal was not specified, but it came after dozens of videos of torture from inside a prison in the central city of Saratov were published recently by Russian human rights group Gulagu.net.
"The incidents of torture in the colonies and pretrial detention centers of the Saratov region and other regions, which received a wide public response, became the main reason for Kalashnikov's resignation," an unnamed source told Interfax news agency.
The videos were smuggled out of the prison by a former inmate, Belarusian IT engineer Syarhey Savelyeu, who has since fled Russia and asked for asylum in France. Russia placed Savelyeu on a wanted list last month, but then removed him from it.
Earlier this month, FSIN said it had dismissed 18 officials in the Saratov region in connection with the videos and opened several investigations.
The Kremlin had previously called for the case to be investigated.
Russia's huge prison network has long been known as a place of torture and sexual violence inflicted on inmates, according to human rights groups, but the videos cast new light on abuses.