A US hacker has been sentenced to five years in federal prison for laundering billions of dollars in cryptocurrency stolen in one of the largest thefts in digital currency history.

Ilya Lichtenstein pleaded guilty last year to laundering almost 120,000 bitcoin taken in a 2016 hack of the cryptocurrency exchange Bitfinex. At the time of the theft, the stolen bitcoin was valued at around $70 million, but it had surged to over $4.5 billion by the time of Lichtenstein’s arrest.

Lichtenstein’s wife, Heather Morgan, played a key role in laundering the funds, using the alias “Razzlekhan” to promote her hip hop music while allegedly aiding in covering up the crime. Known for her bold, expletive-laden music videos, she described herself in lyrics as a “bad-ass money maker” and “the crocodile of Wall Street.” Morgan also positioned herself as a tech entrepreneur, contributing articles to Forbes where she claimed to be an “economist, serial entrepreneur, software investor, and rapper.”

Lichtenstein and Morgan employed complex laundering methods, according to the Department of Justice, using fake identities, converting funds into other cryptocurrencies, and purchasing gold coins. Prosecutors revealed that Lichtenstein even met with couriers on family trips to transfer laundered money back home.

The Department of Justice’s $3.6 billion asset recovery in this case marked its largest-ever financial seizure. Deputy Attorney General Lisa Monaco described it as a critical message that cybercriminals cannot act with impunity. District Judge Colleen Kollar-Kotelly echoed this sentiment during sentencing, emphasizing the need for accountability.

Lichtenstein expressed remorse in court, stating his intention to use his skills to combat cybercrime once his sentence is complete. Morgan, who also pleaded guilty last year, is due to be sentenced on November 18.