CANBERRA -- Two of Australia's big four banks have been accused of criminal offences over their treatment of superannuation customers.

In a submission to the Royal Commission into Misconduct in the Banking, Superannuation and Financial Services Industry, Michael Hodge, senior counsel assisting the commission, recommended that the Commonwealth Bank of Australia (CBA) and National Australia Bank (NAB) face criminal charges.

The CBA is Australia's largest bank while NAB is the second largest.

According to Hodge, CBA knowingly breached superannuation laws 13,000 times when it failed to move 13,000 superannuation members to low fee, no commission accounts before the Jan 1, 2014 legal deadline.

Hodge recommended that NAB knowingly broke the law 84 times between 2014 and 2017 over failing to notify the Australian Securities and Investments Commission (ASIC), Australia's finance sector watchdog, that it charged customers fees for services it never delivered.

"It is submitted that this behaviour indicates a disregard on behalf of the NAB Group for members of the relevant superannuation funds, for regulators and for the law," Hodge told the commissioners, as detailed in the commission's preliminary report, which was published on Friday evening.

The bank has already begun paying 90 million Australian dollars ($65.9 million) back to 300,000 superannuation customers who were wrongly charged the fees.

According to the report, Hodge was also critical of ASIC and the Australian Prudential Regulation Authority (APRA), the banking regulator, over how they performed their duties.

"The approach of neither APRA nor ASIC to regulation of superannuation entities is sufficient to achieve specific or general deterrence," he said.