This horrifying footage shows an inmate screaming out in pain as he is apparently pinned down and cut with a metal blade behind bars.
The video was purportedly filmed at Wormwood Scrubs jail in west London, where another prisoner was found stabbed to death in January.
Posted on Instagram, it appears to show the shrieking inmate desperately trying to shield his head as he is attacked at the Category B facility.
Two men's voices can be heard in the footage, with one saying: "Listen - so why do you snitch on Albanians, bro?", Get West London reports.
Vidmax.com - Crazy, Cool, and Wild Reality Videos