The presumed boss of the Sicilian Mafia in Montreal will be released from a US prison next month after serving part of a 10-year term stemming from the killing of three rival mobsters, a government agency said. The Federal Bureau of Prisons said Vito Rizzuto, 66, will be getting out October 6 after serving five years behind bars in a high security prison in Colorado, but did not state the reason why. It was not immediately clear, however, if US immigration authorities will allow Rizzuto to return immediately to Canada, a Justice Department official told AFP. His return could re-ignite a battle between the Rizzutos and rivals from the Calabrian mafia. Rizzuto was arrested in Canada in 2004 and extradited to the United States in 2006, then convicted a year later for his role in the 1981 murder of three Bonanno crime family members in New York City. He pleaded guilty to racketeering and conspiracy to commit murder, and was fined $250,000. He had appealed in vain several times previously for early release, the last time in August.