A banks deposit receipt obtained by Sydney student Yi Feng as part of his involvement in a $4m proceeds of crime operation "No you didn't – you haven't spoken to him for months," the presiding judge, Anthony Blackmore, replied after viewing the file. The young man from Beijing seemed shocked as he was informed that he was likely to face a jail term and thus his bail was to be revoked . But an agreed statement of facts in the case reveals that a lengthy stay in prison was always a realistic possibility. It shows that within two weeks of arriving in Australia on a tourist visa in July 2014, Feng began taking bags full of cash to Commonwealth and Westpac Bank branches across the country and depositing the money into more than a dozen different accounts.

By December 8 of the same year – less than five months later - the University of NSW student had made 68 such deposits totalling $4,056,930. The deposits ranged from $20,000 to $80,000 and were often spread out across a number of different accounts which had non-descript names such as Auschain Investment Trust and George Xie's Investments Pty Ltd. When police examined Feng's iPhone they found a series of online conversations made through the app 'WeChat' in which the student received his instructions from a man he referred to as "brother". On some occasions the man known as "brother" – who cannot be named for legal reasons – would enquire as to whether Feng was available to "work" the following day, while at other times Feng would contact him, asking "any jobs tomorrow brother?" "I have enough rest recently but I don't know if you put me on the roster," the young student said in one message.

According to the agreed facts, a series of messages and phone calls would ensue to arrange a meeting point, after which the cash would be handed over along with instructions as to how much to deposit and to whom. Once he had completed the deposit Feng sent "brother" a screenshot of the bank slip by WeChat which verified the transaction. "Feng was willing to travel to deposit money and he structured his lifestyle and attendance at university around this travel by skipping classes that he considered unimportant," the agreed facts state. On a number of occasions the 19-year-old recruited his colleagues to help with the "work". But it did not stop him getting badly behind in his studies.

"Brother I got trouble here - I received second warning letter for my score [sic] is under 70," he wrote in one message to "brother". The other man replied "it's ok, concentrate on your class". Having investigated Feng for a number of weeks, the police arrested him on December 8 after watching him and "brother" meeting in the Sydney suburb of Rhodes. After the meeting, the 19-year-old went into a nearby branch and deposited $45,000 arranged in bundles of $50 and $100 notes. When police pulled over the car Feng and "Brother" were in, they found a black sports bag containing $150,000 in the footwell.

Feng later admitted to police that he had made a number of deposits at the request of "brother". But he said the older man was "rich" and that he did not ask where the money had come from. Depositing the money had been a "favour" to the other man who had introduced him to people and been good to him. Eventually on October 23 last year, Feng pleaded guilty to possessing proceeds of crime in excess of $100,000. On Tuesday night, a spokesman for Auschain Investment Trust - which received a deposit from Feng - said it had been unwittingly caught up in the crime. The spokesman said that because of restrictions on currency transfers in China, people who wanted to purchase goods or property overseas often used companies to make the transfer.

"We're just a real estate agency," a company spokesman said. "Unfortunately in this case our client, a real estate purchaser, unknowingly used an illegitimate transfer company which completed the transaction in an illegal way. "We would encourage all Chinese purchasers to make sure they're using a legitimate company to transfer money because the system is clearly open to abuse. In this case the purchaser's account has now been frozen." Feng will return to court on June 16 for sentencing.