Infamous Boston gangster James "Whitey" Bulger has been found dead in a US federal prison in West Virginia.

Axar.az reports citing BCC that the 89-year-old was discovered unresponsive at the maximum security facility shortly after being transferred there from a Florida jail.

A prison union official told the Associated Press news agency the death was being investigated as a homicide.

The life of Bulger, who was convicted in 2013 of 11 murders, inspired several films.

He was captured in California in 2011 after a 16-year manhunt.

The former leader of South Boston's Winter Hill gang inspired the film Black Mass featuring Johnny Depp, and The Departed, which won the Academy Award for best picture in 2007.