The family of a Cairns-based pilot shot dead in Papua New Guinea want Australian police to investigate whether his murder was a contract killing.
Captain Alan Mourilyan was shot dead in Mt Hagen in March by armed robbers after taking money from his bank account at an ATM and handing it over.
PNG police have described the attack as a gang robbery gone wrong.
But Mr Mourilyan's family have since hired an Australian private investigator after having doubts about the PNG police investigation.
This week they plan to contact Australian Federal Police to ask that police being deployed in PNG under the enhanced co-operation program investigate the murder.
The family is concerned that the circumstances of the shooting, including the small amount of money taken, raised suspicions it was an arranged hit to the benefit of someone in Australia.
PNG police have said the man who pulled the trigger on Mr Mourilyan had been captured and was in jail awaiting trial but a second man wanted for the shooting was still at large.