Nicolo Rizzuto is on probation after pleading guilty to two gangsterism-related charges. (Graham Hugues/Canadian Press)

Nicolo (Nick) Rizzuto, the presumed patriarch of Canada's most well-known Mafia clan, has pleaded guilty in Montreal to tax evasion.

Rizzuto, 85, showed up for his brief hearing at the Montreal courthouse Thursday morning, where he entered his guilty plea as his lawyer stood nearby.

He was accused of failing to declare interest revenues in 1994 and 1995 on more than $5 million deposited in three Swiss bank accounts.

The judge ordered Rizzuto to pay a $209,000 fine and taxes on the Swiss accounts.

The Crown attorney couldn't say why it took the Canada Revenue Agency so long to finalize the tax evasion investigation.

Father of reputed Mafia boss

Rizzuto flashed reporters a smile on his way out of the courthouse after his 10-minute hearing.

He is the father of reputed Mafia boss Vito Rizzuto, who is serving time in a U.S. institution for racketeering.

Rizzuto attends a funeral service in January for his grandson Nick Jr., son of Vito. (Paul Chiasson/Canadian Press)

He is also grandfather of the recently slain Nick Rizzuto, who was gunned down in broad daylight in Montreal last December in what many observers called an underworld retaliation.

Nicolo Rizzuto is already on parole on separate gangsterism-related charges, to which he pleaded guilty last year and was handed a suspended sentence.

He was arrested in 2006 after a massive four-year police investigation that targeted more than 70 alleged members of Montreal's Mafia organization.

With files from The Canadian Press