They have also uncovered a second crime scene close to the original crime scene in bushland about 20km out of the city.

Details of the motive or the second crime scene were not released yesterday.

However, the new information has sparked a renewed call by police in Mount Isa and Brisbane for public help to solve the murder.

Mr Macfarlane, 30, died early Wednesday morning January 4 in the Mount Isa Hospital after he was shot in the chest on the evening of January 3.

Police from Mount Isa Criminal Investigation Branch and the Homicide Investigation Unit, State Crime Operations Command are continuing a major investigation, codenamed Operation Kilo Field.

A white Holden Commodore involved in the transportation of Mr Macfarlane to the hospital on January 3 was seized and police are waiting for results of the forensic examination. It's believed this could take several weeks.

Police yesterday said they believed they had established the motive behind the murder and identified a person of interest in their investigation.

Door knock inquiries continue in Mount Isa in addition to the questioning of associates of the person of interest and potential witnesses to try and establish the movements of Mr Macfarlane before and immediately after his shooting.

Anyone with further information is asked to contact Crime Stoppers on 1800 333 000.