Sydney millionaire Ron Medich should be locked up for the rest of his life for directing the execution-style murder of a hated business enemy, a judge has been told.
The 2009 contract killing and subsequent intimidation of his victim's widow involved a "wickedness" and callousness warranting a life sentence, prosecutor Sharon Harris said on Thursday.
But Medich's barrister Winston Terracini SC argued against a life term, while stressing his client maintained his innocence.
He compared a life term with shorter sentences imposed on others involved in the murder, including the shooter Haissam Safetli who was prepared to kill a stranger "purely for money".
Medich, 70, was found guilty by a Supreme Court jury in April of murdering Michael McGurk in September 2009 and intimidating his widow Kimberley McGurk almost a year later to try to get her to pay her husband's alleged debt.
The 45-year-old was gunned down outside his luxury north shore Sydney home after he and Medich had become embroiled in ongoing and protracted legal battles involving millions of dollars.
The Crown submitted that Medich had provided $600,000 for the murder and the intimidation.
"The particular facts of this case are so serious that a sentence of life imprisonment is warranted," Ms Harris said.
"In particular, the Crown relies on the fact it was a contract killing.
"Payment was made by the offender in order to kill the commercial foe of the offender."
Medich's involvement included the direction, the financing and the encouragement of the murder during the months in which the killing was afoot.
The millionaire had complained about the delay to his then confidant, Lucky Gattellari, and put pressure on him to get the job done.
"There was ample time for calm reflection by the offender to withdraw his directions," Ms Harris said.
Medich had a financial motive in wanting to recoup money and property he believed was his and put an end to what he believed was an embarrassing situation.
Mr Terracini referred to his client's previous good character and his age, while disagreeing with the Crown that he may be a danger to the community if released from a non-life sentence.
Medich would likely then be in his 90s, he said.
Justice Geoffrey Bellew will sentence him on June 21.