The Financial Conduct Authority has fined Standard Bank PLC £7.6m for failures in its anti-money laundering controls.
The penalty also relates to procedures over corporate customers connected to politically exposed persons.
This is the first AML case the FCA, or its predecessor the Financial Services Authority, has brought focused on commercial banking activity.
This is also the first AML case to use the new penalty regime, which applies to breaches committed from 6 March 2010. Under the new regime larger fines are expected.
{desktop}{/desktop}{mobile}{/mobile}
Tracey McDermott, director of enforcement and financial crime, said: "One of the FCA's objectives is to protect and enhance the integrity of the UK financial system.
"Banks are in the front line in the fight against money laundering.
"If they accept business from high risk customers they must have effective systems, controls and practices in place to manage that risk.
"Standard Bank clearly failed in this respect."
Standard Bank is the UK subsidiary of Standard Bank Group, South Africa's largest banking group.