The man once known as Montreal’s ‘Teflon Don,’ reputed mob boss Vito Rizzuto, has died in hospital.

Rizzuto, 67, died at Sacre-Coeur Hospital in Montreal early Monday morning of "natural causes", a hospital official confirmed to CTV News.

The hospital declined to provide further details about his death, citing patient confidentiality.

Rizzuto returned to Montreal in October 2012, after he was released from a U.S. prison where he served six years for racketeering and conspiracy in connection with the 1981 triple murder of three New York City Mafia captains.

"The minute he got out of jail, Rizzuto started rebuilding his empire," said CTV Montreal's Stephane Giroux.

Giroux said a number of individuals who took care of Rizzuto's business died while he was in jail.

Rizzuto’s father, Nicolo Rizzuto, was 86 when he was shot with a high-powered rifle by an individual hiding behind his home in November 2010. The shot pierced the kitchen’s bullet-proof glass window, striking the elderly Rizzuto in the jaw while he was eating.

Rizzuto’s son Nick Rizzuto Jr. was killed in a brazen daytime shooting just days before Christmas in 2009.

Both murders remain unsolved.

Adrian Humphreys, who co-authored the book, “The Sixth Family: The Collapse of the New York Mafia and the Rise of Vito Rizzuto,” along with Lee Lamothe, says there's no apparent successor in the wake of Rizzuto's death.

“The death of Vito Rizzuto changes the entire landscape of the underworld in Canada and in many ways to a lesser degree, around the world,” Humphreys told CTV Montreal.

And Lamothe says he laughs “whenever they call (Rizzuto) the Canadian John Gotti.”

While the American crime boss’s influence was mostly limited to New York, Florida and the U.S. Midwest, Rizzuto’s empire stretched across the world.

“Rizzuto was a big fish in a big pond and he was the biggest fish — I'm talking globally," he told The Canadian Press.

Rizzuto arrived in Montreal in 1954 at eight years old, and grew up in the city’s Italian districts of Villeray and St-Leonard.

A few years later, his father became the boss of a Montreal Mafia organization, and by 1980, the Rizzuto family had become the leading Mafia family in Montreal.

But Rizutto’s extradition to the United States on a racketeering charge in 2006 crippled the family’s lengthy hold on power.

After his releasein 2012, Rizzuto remained relatively out of sight. His name, however, was often brought up at the Charbonneau commission over his clan’s alleged control over city contracts in Montreal.

His death is expected to create a major power vacuum within the Mafia, and with no obvious heir, some lesser known figures may try to take over.

"Now that he's gone it's going to unleash a lot of unprecedented jockeying for his position, for his power and for his financial empire," Humphreys told CTV Montreal. "It's all going to be played out on streets across Canada."