Nicolo Rizzuto, considered the head of the most important mafia group in Montreal, has been shot dead at his home in a move being blamed on rival crime clans, police and Canadian media said.



Police in Montreal confirmed the death on Wednesday of a man of Sicilian origin after Radio-Canada and TVA television said the 86-year-old immigrant from Sicily was assassinated.



The killing is a major blow to the Sicilian mafia group that has been active for 30 years, but whose power appeared to be fading.



Rizzuto arrived in Canada in 1954 and rose to prominence in the organised crime area after the death in 1978 of mob boss Paolo Violi, a Calabrian rival.



A journalist at the daily La Presse, Andre Noel, who co-authored a recent book documenting Quebec's mafia groups, suggested the killing was an extension of that historical rivalry and the Calabrian group appeared to be on the offensive against Rizzuto's clan.



"Such an attack has taken place in Europe ... it is likely the same thing happened here," Noel told AFP.



Another expert on Canadian mafia groups, Antonio Nicaso, said the killing could also be the action of a "coalition" of different mafia groups in North America who have split with the Sicilians.



Last December, Rizzuto's 42-year-old grandson Nick was killed by gunfire in broad daylight on a Montreal street - a murder similarly blamed on rival mafia groups, with the victim the heir apparent to the clan leadership.



Nick's father - Vito Rizzuto, Nicolo's son - had earlier compromised the family operation with his 2004 arrest on US racketeering charges, leaving Nicolo to run the group along with several trusted lieutenants.



In 2006, Vito was extradited to the United States and prosecuted in connection with the 1981 murder of three Bonanno crime family members, earning a 10-year sentence.



Then in November 2006, Canadian police launched a massive crackdown dubbed "Operation Coliseum", which led to Nicolo Rizzuto's arrest and conviction.



He was sentenced to four years in prison and sent to jail along with a number of his associates, though he was later released under strict monitoring.



AFP