The body of an alleged Mafia boss who once headed a notorious New York crime family was found by a river near Montreal on Thursday.

Police haven't officially named the victim, but multiple reports identify the body as that of Salvatore Montagna.

Just after 10 a.m. a passerby called police after spotting a body along the shores of the L'Assomption River, north of Montreal.

"When (police) arrived, they saw a man lying near the river, they took him out of the water and started doing CPR with the help of emergency personnel," Sgt. Benoit Richard told The Canadian Press.

Richard said the victim was transported to hospital where he was pronounced dead.

Police refused to confirm how the person died, however the passerby reported that he had heard gunshots.

CTV Montreal's Rob Lurie reported that a witness also saw Montagna running out of a house with someone chasing him.

The FBI once called Montagna, nicknamed "Sal the Iron Worker," the acting boss of the Bonnano family. The family is one of the notorious criminal gangs that formed the original Commission, along with Al Capone and Lucky Luciano.

The Bonnano crime family is one of the five largest Mafia families in New York. The family also had close ties to the Montreal Mafia.

Montagna, 40, was born in Italy and raised in Montreal. He was deported to Canada from the United States in 2009.

An autopsy is scheduled for Friday.

With files from The Canadian Press