Criminal proceedings have been launched by The Financial Conduct Authority (FCA) against NatWest over allegedly failing to comply with money laundering rules.
The City watchdog has claimed that increasingly large deposits were made into a UK customer account, alleging around £365m was paid in, including £264m in cash.
It also alleges that the bank's systems and controls failed to adequately monitor and scrutinise this activity, which took place between November 2011 and October 2016.
In a statement, NatWest said it had been co-operating with the FCA.
It added: "Since being notified of this investigation in July 2017, NatWest Group has disclosed that the FCA was undertaking an investigation into NatWest Group's compliance with the MLR 2007. NatWest Group has been co-operating with the FCA's investigation to date.
"NatWest Group takes extremely seriously its responsibility to seek to prevent money laundering by third parties and accordingly has made significant, multi-year investments in its financial crime systems and controls."
NatWest is scheduled to appear at Westminster Magistrates’ Court on April 14.
This is the first criminal prosecution under the MLR 2007 by the FCA and the first prosecution under the MLR against a bank.
No individuals are being charged as part of these proceedings.
