Lucky Gattellari said he checked with his friend Ron Medich several times. Did he really want Michael McGurk killed?

"F---en oath," came the alleged reply.

It was 2009 and Mr Medich, a wealthy Sydney property developer, was increasingly embarrassed and angry, Gattellari told the NSW Supreme Court on Monday.

Mr Medich, 69, had become entangled in a series of costly lawsuits with Mr McGurk.

"This f--ing bastard is ruining my life," Mr Medich complained, according to his then business partner Gattellari, 68.

"People in the eastern suburbs think I'm a fool."

One day at his office in Leichhardt, Mr Medich asked "would I possibly help him out finding someone to kill the bastard", Gattellari told the court.

"I said look, there's no coming back from something like this - are you sure you want it done?"

Mr Medich would not be deterred, said Gattellari, who is still serving a jail sentence for his role in the contract killing.

Gattellari had been carrying out debt collection for Mr Medich and employing two brothers, the Safetlis.

He said they had previously offered to help him if he ever needed anything "heavier" or "the final job done".

After the alleged instruction from Mr Medich, Gattellari went to the Safetlis, who quoted $300,000 plus expenses for the murder.

But, including the alleged intimidation of Mr McGurk's wife after the killing, it would be closer to half a million dollars, Gattellari told Mr Medich.

He described to the court how he and his driver went to the Medich home at Point Piper, taking the lift down to the bottom floor where Mr Medich met them and said after a brief chat, "I'll go get the dosh."

Mr Medich allegedly came back with a shopping bag with $250,000 in cash inside, split up in vacuum-packed plastic bags of $10,000 each in $50 notes.

The transfer of the second instalment was said to have taken place in much the same way after the murder.

Mr McGurk, 45, was shot in the back of the head on September 3, 2009, in the driveway of his Cremorne home, right next to his young son.

Gattellari, whose sentence was shortened in exchange for his testimony, told the court he had only met Mr McGurk four times and thought he was a "a bit of a conman".

He was once angered by a critical remark Mr McGurk made about the electrical businesses Gattellari helped run and Mr Medich was funding to the tune of $16 million.

Gattellari said another time Mr McGurk approached him to ask if he would help "sort out" a witness in a court case that was giving him trouble.

"I said to him I don't do that sort of thing, Michael."