A Melbourne court heard on Thursday that Pete Hoang, 36, was arrested with the money by Australian Federal Police at Crown Casino in October, 2012, after he planned to gamble about $1 million of it.

His barrister David Grace, QC, told Melbourne Magistrates Court that his client had a gambling turnover of $90 million in the five years before his arrest.

He was a gambler and "that's what he does and that's how he survives", Mr Grace said.

He said Mr Hoang had recently won $2.5 million at the Adelaide casino and twice last year won Tattslotto, with prizes totalling more than $600,000.

He applied on Thursday to vary his client's bail to have his seized passport returned to allow him to visit Vietnam for a holiday and to see his foster parents.

Andrew Buckland, prosecuting, opposed the variation on the grounds that there was a "very real risk" Mr Hoang would not reappear to face a contested committal hearing in June.

Mr Buckland told magistrate Susie Cameron that if found guilty, Mr Hoang, an Australian citizen, faced a sentence of 12 months or more with the charge attracting a maximum of three years.

He submitted that on an analysis of his financial details by a prosecution expert, Mr Hoang had no known legitimate source of income and that he was an unsuccessful rather than a successful gambler despite winning $7.9 million at casinos between 2000 and 2012.

Mr Buckland said the analysis revealed he had about $7.1 million of "unsourced" money he had "pumped" into casinos.

Mr Buckland said the accused told police in a record of interview his only jobs had been waiting tables and working as a salesman for Telstra before receiving about $50,000 in youth training allowance for six years from 2001.

He told Ms Cameron that Mr Hoang did not own property in Australia, had no family ties, lived relatively modestly in a rented room in Bankstown, NSW, and drove a 2006 Lexus.

The "crux" of the case, he argued, was that Mr Hoang over several years had accessed "very, very large amounts of money", apparently spent at casinos, and that to seek to go on a holiday before the committal presented a real risk he would not answer his bail.

Mr Grace said the prosecution, through its analysis, will seek to dispute his client's assertion to police that the $1.495 million subject to the charge was casino winnings.

The issues at the committal will be whether it is reasonable for police to suspect the money is proceeds of crime and also whether the prosecution analysis "stands up to scrutiny".

There was a statement on the prosecution brief that revealed Mr Hoang was a high roller who gambled at the exclusive Crown Casino Mahogany Room and was provided transport and accommodation by the casino.

Mr Hoang had obeyed his bail conditions since his arrest and had a case manager with the financial services ombudsman prepared to put up her house as surety, he said.

In refusing the application, Ms Cameron said she had carefully considered all submissions and had found it was not reasonable to vary Mr Hoang's original bail condition that he surrender his passport.

Ms Cameron said he had not "advanced any compelling reason", such as a hardship issue, to warrant the variation, and she noted he "clearly faced" jail if convicted.

Mr Hoang represented a risk of failing to appear, she said.