Philip Jepson Egglishaw is alleged to have set up a $300-million network of tax evasion.
However, Australian authorities were unable to bring any criminal proceedings against him when he moved to Geneva because Swiss law enforcement did not act on an Interpol Red Notice issued for his arrest.
Mr Egglishaw was eventually caught in May after checking into the £1,500-a-night Villa d'Este hotel with his partner, Sheila Jordan, in Lake Como – about 12 miles from Switzerland.
In line with Italian law, hotels must forward their guests' passport details to the police each night.
Mr Egglishaw was arrested by officers the following morning and it is understood that he is now being held in prison, ten miles away in Bassone.
After appearing at a private hearing in the Milan District Court, Mr Egglishaw's lawyer is said to have told News Corp that his client disputed the charges against him and that the 'statute of limitation' – the period in which he could be extradited to Australia – had passed.
Mr Egglishaw, a former Hautlieu student, told the court he would resist the extradition application.