Humza Zaman was sentenced to 46 months incarceration and three years supervised release as well as given a $75,000 fine by a court in Boston after pleading guilty to one count of conspiracy last April.

Zaman laundered between $600,000 and $800,000 for Gonzalez, who is awaiting sentencing after pleading guilty to a string of cyber-attacks on several firms, resulting in the theft of tens of millions of payment card details.

According to court papers, Gonzalez often asked to be paid for card numbers in digital currency or by wire to a bank account in Latvia.

In November 2005 Zaman used ATM cards linked to accounts in the names of fictitious or unrelated individuals to withdraw and repatriate from Latvia around $38,000 of Gonzalez's funds and sent the money in cash, minus a cut, to the hacker in Miami.

Then, in late 2005 and early 2006 Zaman went to California for Gonzalez on three occasions, picking up between $50,000 and $370,000 from an unknown man and then, after taking his cut, shipping the cash to Gonzalez in Federal Express boxes. A similar process was carried out from New York.

Around two years later, in March 2008, Zaman sent Gonzalez ATM system logs from Barclays, where he was working as a programmer, to see whether they could be of use to the cyber thief. Although Gonzalez uploaded these logs to a Latvian computer server, there is no evidence that the data was used.

Gonzalez is facing a minimum 17-year prison sentence after pleading guilty to a string of attacks on several firms, including TJX and Heartland Payment Systems.

Last year, another of his co-conspirators, former Morgan Stanley software engineer Stephen Watt, was sentenced to two years in prison for developing the software used to capture payment card data.