Commonwealth Bank boss Ian Narev concedes an independent review found that one in 10 customers who asked for a review of financial advice were then inappropriately advised by the bank.
Mr Narev on Tuesday was quizzed by a federal parliamentary committee about the bank's ongoing review of the scandal in its financial planning arm several years ago which led to the banning of some of its advisers.
He told MPs an independent report last week found of 8000 customers who asked for their financial advice to be reviewed, 6000 had been completed.
It found more than 10 per cent of those were given inappropriate advice.
The bank had paid out $11 million in claims since its initial payout of $52 million several years ago.
Mr Narev defended the time it had taken to resolve the matter and said it would be wrapped up by the end of the year.
"We've gone back a large number of years in this program to statements of advice that go back prior to the global financial crisis," he said.
"So yes it has taken a period of time to do that but we've done it thoroughly, with independent oversight."
The House of Representatives economics committee will seek documents on the bank's internal investigation of the scandal as well as details on action taken by the bank to address it.
Mr Narev insisted the bank was doing better at listening to customers and was committed to efficient redress.
"We found 800 cases where customers were owed remediation - that's out of a base of hundreds of thousands of customers who received advice during that time.
"I'm not saying 10 years ago, five years ago, even two years we were doing as well as we need to and I think today there's still work to do."
