Russian authorities said they had fired five senior prison officials Wednesday (October 7).
And claimed to have opened criminal investigations into alleged torture and sexual assaults at a jail in the Saratov region.
It comes after a prisoner rights group – Gulagu.net – began publishing what it said was graphic video evidence of orchestrated sadism at the prison.
The group said it had received a massive leak of documents, photos and videos.
They allegedly showed that hundreds of people across the prison system had been tortured and raped by other inmates at the direction of prison officials.
Gulagu.net founder Vladimir Osechkin.
"Currently, we have gathered overwhelming evidence that proves instances of torture in Russia have been set up literally by the intelligent services, that these instances of torture were systematic and carried out with the help of the 'activists'."
The footage has caught the eye of the Kremlin.
On Tuesday (October 5), it said there were ground for a serious investigation if it was found to be authentic.
Russian prison conditions were already in focus after jailed Kremlin critic Alexei Navalny drew attention to it earlier this year.
Russian law says inmate must not be treated in a way that is "harsh" or "abases human dignity".
If a prison official abuses their position he can be jailed for up to a decade.