Notorious Boston gangster James “Whitey” Bulger, who was found dead Tuesday, was gruesomely beaten to death in his wheelchair by four men at a West Virginia prison Tuesday, according to a report.

The four individuals beat Bulger, 89, with a lock in a sock and used a type of shiv to try and gouge out his eyeballs, sources within U.S. Penitentiary, Hazelton in West Virginia told TMZ.

The attackers also attempted to cut off his tongue, though it's not clear if they were successful.

TMZ's sources said the attack was likely mob retaliation.

Bulger, the former leader of the Winter Hill Gang, was convicted in 2013 of participating in 11 murders across the U.S. and was serving a life sentence. He was also a secret informant to the FBI.

[More: 'Misery Mountain': The jail where 'Whitey' Bulger was slain has history of murder and violence]

Bulger was first reported Tuesday afternoon to have been killed in a common area, but TMZ said his suspected attackers went after him while he was sitting alone in his private cell at around 6 a.m. Tuesday.

Surveillance cameras caught the men entering the room, but not the attack.

The suspects were then seen exiting Bulger's cell with blood on their clothes. They then went back to their cells, changed into clean clothes, and returned to Bulger's cell with a mop and bucket to clean up the room.