Treasurer Josh Frydenberg says he will ‘favourably consider’ any request to extend the banking royal commission, after the inquiry confirmed regulators had been far too soft on bad behaviour.

Mr Frydenberg has offered royal commissioner Kenneth Hayne more time to conduct his investigations, with an interim report due later this month and a final report expected in February.

‘We will leave no stone unturned in getting a better financial system which is better customer-focused for the Australian people,’ he told ABC radio on Monday.

Mr Frydenberg says corporate regulators ‘certainly have a case to answer’ after failing to act on a litany of offences by financial institutions.

The royal commission has uncovered numerous examples of customers being charged fees for no service, dead people being hit with bills, lying to regulators and hundreds of thousands of breaches on insurance advice.

‘This is certainly not good enough,’ Mr Frydenberg said.

‘I want to understand why ASIC did not stamp out this bad behaviour and didn’t engender a better culture within the financial services sector.’