The man once dubbed Australia's worst landlord has been slugged with a $3.3 million tax bill despite his being dead for more than two years.
The move comes as Frank Cassar's heirs continue to reap a windfall from the vast property empire of the notorious Melbourne slum lord, which is now worth more than $9 million.
But Mr Cassar's son, Michael, has denied the claim and taunted the Tax Office to try to collect its bill.
''They won't be getting a quarter of what's alleged,'' he told Fairfax Media. ''It's a lot of garbage, just like the stories you lot have fabricated about my father.''
Mr Cassar, who died in October 2011, was given the sobriquet ''Australia's worst landlord'' after racking up at least nine convictions, 45 civil judgments and more than $50,000 in fines as the operator of a dozen inner-city rental properties.
Court records show Mr Cassar and his wife, Sandra, routinely withheld deposits, failed to lodge bonds with proper authorities, defied court orders, and kept their properties - which were often rented room-by-room to transient tenants - in a decrepit condition.
Mr Cassar, who had convictions for assault and hindering police, was also known for evicting, harassing and threatening tenants who complained.
In the year before his death, a Tax Office audit revealed Mr Cassar owed more $2.3 million in income tax from his rental and other businesses, which he and his family have refused to pay.
But the Tax Office is now looking to force Mr Cassar's wealthy estate to foot the bill, which has ballooned to more than $3.3 million with interest and penalties. The collection action, launched in the Supreme Court earlier this year, is believed to have come after the Tax Office discovered Michael - as his father's executor - had sold the family home in Kew for $4.25 million in June last year.
And the family is poised to continue to profit handsomely from Frank Cassar's tenure as Australia's worst landlord, with an investigation revealing his estate holds eight properties in Fitzroy and Fitzroy North that are conservatively valued at more than $9 million.
Michael has declined to comment on the rental business or his plans for the properties.
''I've got plenty of money; I'm my father's son. Take care,'' he said.
There are also unpaid state land tax bills on five of the properties.
Meanwhile, the family has continued to lease out a number of the properties, some of which return more than $900 a week in rent.
In July 2011, Frank Cassar and his wife were barred by the Supreme Court from having any direct contact with tenants and that ban was eventually extended to include Michael. All business must be conducted through a licensed real estate agent.
A Consumer Affairs Victoria spokesman declined to comment on whether the Cassars were the subject of an open investigation into their operation of the properties.