One was the devoted father and school fundraiser laid to rest on Friday to the accompaniment of a lone bagpiper.

The other was the ruthless property developer, loan shark and debt collector, who was not afraid to use violence and inspired fear in those who crossed him.

McGurk’s murder, and its tangled ramifications, has riveted Australians since he was shot dead outside his house 10 days ago in front of his nine-year-old son, Luc. Each day brings a new batch of sensational revelations, revealing the murky side of Sydney society and threatening to draw in senior figures from politics, sports and business.

Even the Sultan of Brunei has been dragged into the story – as part of a bizarre blackmail plot.

The problem for police, as they delve into McGurk’s complex business dealings, is not identifying a suspect, but ploughing through the long list of individuals with a grudge against him.

“I can understand that there were people who were afraid of him,” said one of his associates, Jim Byrnes. “People who have had altercations with Michael, some have come out and said that they’re quite relieved at his death.”

McGurk, who emigrated to Australia in 1993, grew up in the Gorbals. In those days he was known as Mick Rushford. He changed his name after reaching Sydney, where he worked as a lighting salesman, and became six years younger, altering his birthdate to 1958.

His first job ended badly when McGurk secured a contract with a five-star hotel and substituted cheap lights for quality fittings.

He soon moved into more lucrative work. He bought a large house in Cremorne, an affluent harbourside suburb, drove a Mercedes S-Class, took luxury holidays and sent his children to Sydney’s most exclusive Catholic school.

The father of four had risen far above his dirt-poor roots. Yet all was not as it seemed. McGurk was reportedly millions of dollars in debt when he died, and the black S-Class – in which he was shot after pulling up in his driveway – was on the verge of being repossessed.

Embroiled in numerous disputes, most centred on property deals, McGurk had also been charged with arson and assault. The charges – one related to the firebombing of a house in Australia’s most expensive street – were dropped, for no clear reason, last month. But McGurk apparently knew he was a marked man. A week before his death, he told a Sydney journalist, Kate McClymont, that a hitman was on his trail.

A month earlier, he had lunched with McClymont and claimed he had a tape that implicated Australian ­politicians in crooked planning

decisions. That tape has now been handed to police, and the Independent Commission Against Corruption and the state parliament have begun inquiries.

The case has dominated headlines in Australia, with a daily drip-feed of allegations about McGurk. He was a heavy cocaine user and recovering alcoholic. He supplied prostitutes to high-profile figures. He owed a leading property developer £4.15m. It was, a Sydney Morning Herald commentator said, “like a never-ending episode of The Sopranos on the harbour”.

Among McGurk’s associates was Jersey businessman, Mark Burby, who claims his Sydney contact was planning to blackmail the Sultan of Brunei – which in some way was alleged to involve a relative of the Sultan.

Two years ago, McGurk tried unsuccessfully to sue the Sultan, whom he accused of reneging on a deal to buy a 400-year-old miniature Koran. According to Burby, McGurk “had information about an ongoing private matter involving one of the Sultan’s relatives”.

But McGurk, it seems, did not trust Burby. The pair met in the Channel Islands in 2006. Burby said: “I just saw poking out of the top of his sock, his trouser lifted up, the Sony recording device. So he’d recorded virtually the whole two and a half days of discussions.”

None of this fits the image of the man buried after a service at his local Catholic church, presided over by a monsignor. McGurk was mourned not only by his family, but by fellow parishioners and parents from his children’s schools. His father, Bob, and brothers, Eddie and Bobbie, had flown over from Scotland. The coffin was decorated with a Saltire and a Celtic football top. “You are the best dad in the whole wide world,” wrote McGurk’s 11-year-old daughter, Mia, in the funeral programme.