National Australia Bank has potentially committed more than 100 criminal offences overcharging hundreds of thousands of customers fees without providing a service.
The corporate regulator is investigating "suspected offending" by NAB as part of the wider fees-for-no-service scandal across the financial services industry, documents before the banking royal commission reveal.
The banking royal commissioner Kenneth Hayne has refused NAB's bid to suppress documents.
AAP
NAB denies committing any criminal acts.
In the documents about the fees-for-no-service issues, the Australian Securities and Investments Commission accused the bank of failing to report significant breaches of its licence on time on 110 occasions.
Failing to comply with breach reporting requirements is a criminal offence, although the regulator can take a range of administrative, civil and criminal actions.
The number of late breach reports was disputed by NAB, which told ASIC in May it identified 84 significant breaches reported outside the required 10-day time frame.
In the documents, ASIC also said it was concerned NAB contravened sections of the Corporations Act and ASIC Act - some of which may carry criminal as well as civil penalties - over the issue of fees wrongly charged to superannuation members.
