Except for the $1 billion that he gambled at Australia's biggest casino, Crown, in little more than a decade.

Hoang, 36, was shot in the face in September while waiting on a darkened Sydney suburban street. His murder has police baffled, but has also shone a light on a massive money-laundering scheme for a global crime syndicate with links across Asia and the Americas.

Hoang's story, his rise from a Vietnamese-born orphan living on a refugee visa to one of Australia's biggest gamblers and money launderers, also raises concerns about how he was able to rort the system for so long and for so much money – particularly at Australia's biggest casino, Crown in Melbourne.

Court documents from a recent case reveal Hoang ran as much as $1 billion in black cash through Crown between 2000 and 2012. He also gambled under four different names and received perks including overseas holidays, cash gifts of as much as $100,000, and gambling "commissions" in the hundreds of thousands of dollars.

The Australian Crime Commission estimates at least $10 billion a year is laundered in and through Australia; other estimates suggest it is higher. Much of that money is the result of drug trafficking. Most federal crime agencies in Australia acknowledge they face an increasingly monumental struggle against global crime groups seeking to launder their multibillion-dollar narcotics profits here.

Despite being targeted during a 2005 – 2006 Australian Crime Commission operation dubbed Operation Gordian, and with a series of intelligence reports revealing his role as a drug trafficker and money launderer, Hoang remained a fixture at Crown  until he was charged with money laundering in late 2012.

Hoang was also involved with several Vietnamese-Australian drug trafficking syndicates in Sydney and Melbourne. NSW police Homicide Squad commander, Mick Willing,  said there was little doubt Hoang's background in Asian organised criminal syndicates played a role in his death.

"We have certainly considered that he was involved in drug trafficking and moving money through casinos. [That] may have been a catalyst for his death," Mr Willing said.

Born in Vietnam in 1977, Hoang arrived in Australia in 1997 on a student visa and an Indonesian passport under the name Petrus Keyn Peten. Within months he had applied for refugee status, under the name Minh Tan Nguyen. By 2001 he had become an Australian citizen, and changed his name twice more.

By the time he had become a citizen he had already been banned from Sydney's casino, The Star. Law enforcement officials speaking to 7.30 on condition of anonymity said he became a professional money launderer, gambling millions in the profits of heroin and other drug sales.

Intelligence gathered by state and federal law enforcement agencies during the mid 2000s suggests Hoang was involved with a group of Vietnamese-Australians that formed the Australian end of a Hong Kong-based crime group known as Ong Ngoai – or "grandfather" in Vietnamese.

Ong Ngoai is a global drug-trafficking syndicate with links across Asia and North and South America. Australian police have identified at least two dozen drug syndicates here with links to it.

Michael Purchas was the brains behind Operation Gordian and spent months watching Vietnamese-Australian criminals, including Hoang, sell drugs and launder the profits. "He was a known gambler at casinos., [Hoang] would certainly deal with other people's money at casinos under instructions," he said.

Gordian was hailed as a breakthrough investigation into money laundering and resulted in the convictions of members of a small group Vietnamese-Australians responsible for laundering about $93 million in drug profits in a year. At the time Hoang was only a peripheral figure and managed to slip the police dragnet.

He continued to be involved in heroin trafficking and other illicit drugs. The amount of money he laundered through casinos – primarily Crown – also increased.

His luck ran out in October 2012, when he was arrested in a high-roller room at Crown casino attempting to gamble with $1.5 million cash that police alleged  was the proceeds of crime. The court case revealed he had bought about $75 million worth of chips at Crown between 2000 and 2012, which equalled a gambling turnover of at least $225 million, possibly as high as $1 billion.

"This is an amazing amount of money," said Deakin university social scientist and author of a book on Crown casino, Professor Linda Hancock.

"He would be accounting for a very high proportion of gambled funds. He would be what's called in the business, 'a person of interest', so you would think that there would be a trigger between any casino and the police for such a person."

While Crown did report many of Hoang's transactions to federal authorities asitis required to, it also provided him a slew of perks and benefits not available tomost gamblers.

He was allowed to have four different identities at the casino – Pete Hoang, James and John Ho and Patrick Lu – and received free business class flights, accommodation, and alcohol, as well as cash gifts of up to $100,000.

The case also revealed his remarkable gambling patterns. A hearing in June this year received evidence that during the month of September 2012 he bought  more than $9 million in chips and played the card game baccarat at an average of $106,000 per hand.

The casino paid him a commission based on the amount he had gambled, and that month he earned $199,000 as a result of his high-stakes gambling.

Crown casino declined to answer specific questions about Hoang's treatment, but did say: "Crown is and has been for some time assisting state and federal law enforcement agencies regarding Mr Hoang and we will continue to do so."

For more on this story, watch ABC's 7.30 on Wednesday.