A SCOT gunned down outside his home in Australia told a business acquaintance he planned to "expose" the man later accused of orchestrating his murder, a court has heard.

Michael McGurk, 45, originally from Govan in Glasgow, was shot as he parked his car outside his house in Sydney on September 3, 2009, allegedly on the orders of millionaire property tycoon Ron Medich.

The New South Wales Supreme Court was told that businessman Paul Mathieson informed police in February 2009 that Mr McGurk planned to "bring down" Mr Medich by secretly recording a conversation.

Mr Mathieson told officers of a meeting he had with Mr Medich in New Zealand in May 2009 where the property developer was "angry and aggressive" and said "fix" Mr McGurk.

Mr McGurk and Mr Medich started out as friend and business partners, but fell out and were engaged in a costly legal battle.

The trial previously heard how associates of associates of Mr Medich tried to hire dying Aboriginal people for a contract killing.

Mr Medich's former business partner Fortunato "Lucky" Gattellari has already been convicted for his part in organising the killing, but agreed to testify against Mr Medich in return for a reduced sentence.

Ron Mason, a former member of an Aboriginal land council at Narooma, told the murder trial that he was asked if he knew any dying Aboriginal people who might be interested in doing a contract killing.

Several months before the murder of Mr Medich's business associate Michael McGurk in September 2009, Mr Gattellari took him aside while they were having lunch with Mr Medich.

Mr Gattellari told Mr Mason he needed someone "bumped off" straight away as the unnamed person was costing Mr Medich $100,000 a week.

The court heard that Mr Gattellari said to Mr Mason that he must know some Aboriginal people who were dying and didn't have long to live who might like to do the murder.

Mr Medich, a wealthy property developer, has pleaded not guilty to the murder of the Scottish-born wheeler-dealer and the subsequent intimidation of his widow, Kimberley.

The trial continues.