A convicted mob hitman is reportedly being eyed as the person behind the vicious prison beating death of notorious Boston gangster James “Whitey” Bulger.

Bulger, 89, was found unresponsive around 8:20 a.m. Tuesday morning at USP Hazelton in Bruceton Mills, W.Va., where he’d been in custody since Monday, the Bureau of Prisons said in a statement. He was recently moved from a prison in Florida and had a stop in Oklahoma City before moving to the high-security facility in West Virginia.

Bulger had been attacked by three men in the general population sector of the prison, according to TMZ. One of the men used a lock tucked into a sock as a weapon and the group attempted to gouge the gangster’s eyes out and cut out his tongue, the gossip site reported, citing a source. His death was being treated as a suspected homicide.

While no suspects have been officially named, the Boston Globe reported Fotios “Freddy” Geas was being looked at as the man behind Bulger’s death.

Geas, 51, has been serving a life sentence at USP Hazelton since 2015. He was among the group convicted in the 2003 murders of Massachusetts mob boss Adolfo “Big Al” Bruno and his associate Gary Westerman. He was also tied to the shooting of a New York union boss in the same year, Mass Live reported.

Geas, along with his brother Ty Geas and Genovese crime henchman Arthur “Artie” Nigro, was convicted in 2011. A friend turned informant helped convict the mobsters, according to Mass Live. The Geas brothers refused to cooperate in the investigation.

Ted McDonough, a private investigator who worked for Geas, told the Globe he suspected Geas might have killed Bulger and was likely aware Bulger had worked with the FBI as an informant.

“Freddy hated guys who abused women. Whitey was a rat who killed women. It’s probably that simple,” he said, adding that “Freddy hated rats.”

People familiar with the investigation into Bulger’s murder didn’t dispute Geas’ possible role, the Boston Globe reported. Two other people possibly tied to Bulger’s murder weren’t named.

Bulger, who was a fugitive for 16 years, was sentenced in 2013 to life in prison after being convicted of several crimes including racketeering and money-laundering. The jury believed he took part in 11 of 19 killings.

He was one of America’s most wanted criminals until he was captured in Santa Monica, Calif., in 2011.

The medical examiner pronounced Bulger dead on Tuesday after “life-saving measures were initiated” and ultimately proved unsuccessful, the news release from the Bureau of Prisons said.

“The Federal Bureau of Investigation was notified and an investigation has been initiated. No staff or other inmates were injured, and at no time was the public in danger,” the news release said.

Fox News’ Elizabeth Zwirz and the Associated Press contributed to this report.