Bruno Robert Trimbole (/trɪmboʊli/) (19 March 1931 – 12 May 1987) was an Australian businessman, drug baron and organized crime figure whose alleged involvement in drug trafficking in Griffith, New South Wales, resulted in a royal commission, a coroner's inquest and an international chase by the Australian government seeking his apprehension after he fled to Europe.

[4] Trimbole rented a nearby garage and operated as a mechanic, also said to have undertaken his own panel beating and spray painting within the business before declaring himself bankrupt in 1968 with debts of A$11,000.

Through his legitimate businesses, Trimbole had built an empire valued at over A$2 million and, through local confusion and jealousy, had also earned himself a reputation as a major drug baron.

Trimbole soon became the principal of the Australian plant-based cultivation trade based in New South Wales and earned the nickname "The Godfather", a reference to his leadership qualities and Italian background.

Neutral turf was always the race track where all borders abstained while deals were done, Trimbole and Big Bill preferred Moonee Valley racetrack.

Concerned about the growing drug trade in his local area, and learning of a large crop of marijuana in nearby Coleambally, New South Wales, Mackay told Sydney police of the information he had obtained regarding the crop, which resulted in several arrests, and four men of Italian descent being convicted on Mackay's information.

At the scene of his disappearance, his locked van had bloodstains on the door, wheel rim, mudguard and tyre and his car keys and three spent .22 casings were found.

[8] After several months, the Commission reduced the suspect list to six people including: Justice Woodward says in the official transcript, "I have named Trimbole as being associated with the production of marijuana in Griffith as well as being the director of an operation in Euston.

Seven years after the Woodward Royal Commission, political and media pressure called for an inquest into Mackay's death, which was eventually held before Coroner Bruce Brown.

Evidence was also submitted regarding a man by the name of Patrick Joseph Keenan who made a statement to police that he had walked into a shed in the Griffth area and found Antonio Sergi inside with several women packing large quantities of marijuana into plastic bags.

On 5 May 1981, police recorded a conversation between Trimbole and an associate, Dr Nick Paltos, about his pending arrest for conspiracy to murder Mackay.

Trimbole fled to the United States, then to France and finally to Ireland, avoiding customs checks by changing his date of birth on a departure card.