Greek-Australian businessman John Macris was gunned down outside his home as he was getting out of his car in Voula, a suburb south of Athens, late on Wednesday.
Police say that he was shot at least four times.
The 46-year-old was ambushed by as many as three assailants as he was getting out of his car.
Macris had been working in the security services industry in Greece, according to local reports.
He was married to model Viktoria Karyda, and together they had two young children who were home at the time of the shooting.
According to theage.com.au, in 2013 the North Sydney Local Court issued an arrest warrant for Macris after he failed to appear for sentencing over a charge of driving while disqualified.
He was jailed in 2005 for two years and three months for supplying a commercial quantity of drugs and handling suspected stolen goods.
In 2011, his father Stelios was charged with possessing 50 kilograms of meth oil. Alex Macris, John’s brother, testified in court he had “duped” his father into transporting the drugs, and the elder Macris was acquitted.