Twenty of the world's leading banks spent nearly $339 billion over the last five years on costs related to financial misconduct, according to a British research group's annual study.

The figure is $5 billion higher than the previous report's total. That means 10 years after the start of the global financial crisis—followed by years of compliance reforms—the cost of bank misconduct continues to rise.

The five-year study and report are done each year by the Conduct Costs Project, part of the CCP Research Foundation CIC in Great Britain.