The wealthy property developer has pleaded not guilty to the murder of Mr McGurk, 45, who was shot in the back of the head outside his Cremorne home on September 3, 2009.

After the murder, Paul Mathieson told police that, in February 2009, Mr McGurk told him he planned to "bring down" Mr Medich by secretly recording a conversation, which Mr McGurk later confirmed he had done.

Mr Mathieson also told police that he had met Mr Medich in New Zealand in May 2009. On that occasion Mr Medich, who was "angry and aggressive", told Mr Mathieson he was going to "fix" Mr McGurk.

Mr Medich also said: "Don't worry, he won't be a problem for much longer."

Mr Mathieson met Mr Medich in 2003 when Mr Mathieson bought Mr Medich's house in the Sydney suburb of Denham Court.

Mr Mathieson later arranged a $25 million loan facility from Mr Medich for Mr Mathieson's short-term lending company Amazing Loans.

However, the pair later fell out and Mr Mathieson said that Mr Medich had organised for Mr McGurk to threaten him.

However, when Mr Medich and Mr McGurk later fell out themselves, both tried to use Mr Mathieson, who had moved to Hawaii because he feared for his life, to damage each other.

In May 2009, Mr Medich offered him a $7 million loan in return for providing police with a statement implicating Mr McGurk in the firebombing of a Point Piper home.

For his part, Mr McGurk had travelled to Honolulu to try to persuade Mr Mathieson to be part of a scheme to rip off Mr Medich.

Mr Mathieson was not in court to give his evidence. Instead the evidence he had given at a preliminary hearing in 2013 and statements he gave to police were read to the jury by Justice Geoff Bellew, who told the jury that they should not concern themselves about the reasons for Mr Mathieson's absence.

In other evidence, criminal Robert "Bobbie" McCarthy said that, in 2013, he was in Long Bay jail with Lucky Gattellari, who has been jailed over his role in organising Mr McGurk's murder.

Gattellari received a substantial discount on his sentence in return for giving evidence against Mr Medich, his former close friend.

The jury heard that Gattellari had organised for McCarthy to deliver a two-page letter to Mr Medich after McCarthy's release from jail in May 2013.

McCarthy said he could not find Mr Medich, so Gattellari's brother Frank drove him to the house of Mr Medich's brother Roy.

He left a note in Roy Medich's mail box asking him to contact McCarthy urgently. When Roy Medich called, McCarthy informed him that he wanted to have a "sit down" with Ron Medich on behalf of Gattellari.

The court has heard that Gattellari, McCarthy and others have been charged with conspiracy to defraud Mr Medich.

McCarthy's evidence will continue on Monday.