Bank royal commissioner Kenneth Hayne has dealt a blunt reality check to banks hoping to keep sensitive documents away from prying public eyes.

Key points: Royal commissioner Kenneth Hayne reject CBA's application to keep elements of a $10 million settlement with clients concerning over - selling insurance policies secret

Royal commissioner Kenneth Hayne reject CBA's application to keep elements of a $10 million settlement with clients concerning over selling insurance policies secret Justice Hayne said CBA's arguments were "unhelpful and unpersuasive"

Justice Hayne said CBA's arguments were "unhelpful and unpersuasive" CBA told it had already acknowledged its actions in issue "fell short of community standards and expectations"

In dealing with a submission from the CBA to keep parts of an employee statement over an insurance product secret, Justice Hayne agreed to keep the client's details confidential, but not the bank's internal communications or those with ASIC who pursued the bank over the matter.

"In dealing with this particular application it is also necessary to bear well in mind that the conduct … which, in its first submission to the Commission, CBA acknowledged fell short of community standards and expectations and is conduct the consequences of which CBA has sought to remedy by making payments totalling several million dollars," Justice Hayne said.

The CBA had applied to keep evidence under wraps from its executive general manager of retail products Clive Richard van Horen over add-on insurance policies promoted via credit cards, personal loans, home loans and car loans between 2011 and 2015.

ASIC alleged the CreditCard Plus (CCP) scheme was oversold to customers looking to for help to meet repayments if they became sick, injured or unemployed.

The bank was forced to refund 65,000 CCP customers $10 million and pay back another $586,000 to 10,000 customers over insured through its Home Loan Protection consumer credit insurance product.

'Unhelpful and unpersuasive'

Justice Hayne said ordinarily it was "neither necessary nor appropriate to give elaborate reasons for decision".

But in the CBA's case he made an exception. He was clearly not enamoured by the case CBA mounted.

"General assertions are made that certain kinds of communication, such as, for example, communications between CBA and regulators, are confidential," he said.

"Why the particular communications should be treated in this way is not explained."

"Arguments framed in this fashion are unhelpful and unpersuasive," he added.

The royal commission will resume its public hearings in Melbourne on March 13.