''Certainly I don't know the specifics of everything that has happened since I have been there.''

Earlier this month, CBA chief executive Ian Narev announced a new compensation process to determine whether the bad advice was more widespread.

CBA is not revealing how many aggrieved customers of Commonwealth Financial Planning or Financial Wisdom have registered with the scheme.

Mr Norris said regulation didn't always ''necessarily overcome dishonest people''. ''If laws and regulation solved everything, well, we wouldn't have the need for courts to handle anything like that,'' he said.

''It comes down to the fact that it is a case where, when you find these issues, you have got to look at your processes and systems and say, 'What can we do to prevent this from happening again?' That is going to be more effective than a piece of legislation.''