National Westminster Bank (NatWest) on Thursday pleaded guilty to landmark criminal charges brought by the U.K. Financial Conduct Authority (FCA) for money laundering violations.

The case marks the first criminal prosecution brought by the FCA under the 2007 Money Laundering Regulations (MLR).

NatWest pleaded guilty to violating multiple regulations of the MLR that “required the firm to determine and conduct risk sensitive ongoing monitoring of its customers for the purposes of preventing money laundering,” the company stated. The offenses relate to operational weaknesses that occurred between 2012 and 2016, in which NatWest “did not adequately monitor the accounts” of a certain U.K.-incorporated customer (identified as Fowler Oldfield, a jewelry wholesaler that was shut down in 2016 after a series of police investigations).

The guilty pleas followed FCA allegations that increasingly large cash deposits were made into the accounts of the NatWest customer. Of the roughly £365 million (U.S. $498 million) that was deposited in total, around £264 million (U.S. $360 million) was cash. The FCA said NatWest’s systems and controls “failed to adequately monitor and scrutinize this activity.”

“NatWest has cooperated fully with the FCA since its investigation began,” the company stated.

NatWest entered guilty pleas at Westminster Magistrates’ Court. The FCA confirmed it will not prosecute any current or former NatWest employee.

“NatWest is not aware of, and is not anticipating, any other authority investigating its conduct in this matter,” the company stated.

The case now proceeds to Southwark Crown Court for sentencing. NatWest said it will be making a provision in its third-quarter financial statement “in anticipation of a potential fine being imposed at that hearing.”

NatWest is a subsidiary of NatWest Group (formerly the Royal Bank of Scotland Group).

Compliance enhancements: “In the years since this case, we have invested significant resources and continue to enhance our efforts to effectively combat financial crime,” said NatWest CEO Alison Rose in a statement.

NatWest said it has invested nearly £700 million (U.S. $954 million) in the last five years in upgrades to its transaction monitoring systems, automated customer screening, and new customer due diligence solutions, with plans to invest “over £1 billion to further strengthen financial crime controls over the next five years.”

Additionally, NatWest noted it “currently has more than 5,000 staff in specialist financial crime roles, dedicated to detecting and preventing financial crime under the leadership and focus of a centralized bank-wide ‘FinCrime Hub.’”

“NatWest has a vital part to play in detecting and preventing financial crime, and we take extremely seriously our responsibility to prevent money laundering by third parties,” Rose added. “We work tirelessly with colleagues, other banks, industry bodies, law enforcement, regulators, and governments to help find collaborative solutions to this shared challenge. These partnerships are crucial to counter the significant and evolving threat of financial crime to society.”