Former New England Mafia boss Francis "Cadillac Frank" Salemme (sah-LEHM'-ee) has pleaded not guilty in the 1993 killing of a Boston nightclub owner.

The Boston Globe reports (http://bit.ly/2cJf6Kd ) that the 83-year-old Salemme made the plea Thursday in U.S. District Court in Boston to an indictment charging him in the murder of federal witness Steven DiSarro.

An affidavit filed in court also revealed that Rhode Island ex-mobster Robert "Bobby" DeLuca is cooperating with investigators and has implicated Salemme in the murder.

DiSarro's remains were found in March behind a mill in Providence, Rhode Island.

A co-defendant, Paul Weadick, pleaded not guilty last week.

Salemme led the New England family of La Cosa Nostra in the early 1990s and entered witness protection in 1999. He was arrested last month.