The chair of the parliamentary committee investigating the big four banks believes there is enough scrutiny of the sector without the need for a royal commission, as called for by Labor.
Liberal MP David Coleman says last year's inquiry of the banks resulted in a new banking executive accountability regime and a greater oversight of interest rate decisions by the consumer watchdog.
"What we need to do is ensure that every bank executive knows that the representations they're making publicly about interest rates are now subject to deep, internal scrutiny," Mr Coleman told Sky News on Sunday.
This will be regulated by the Australian Competition and Consumer Commission.
The House of Representatives economics committee will grill the chief executives of the ANZ, Commonwealth Bank, National Australia Bank and Westpac again next month.
Mr Coleman said on 20 occasions since the turn of the century bank interest rates have moved out of step with the Reserve Bank.
The banks argued at the previous inquiry there are many other factors than changes in the Reserve Bank cash rate that determined lending rates.
But Mr Coleman said if that was the case then logically sometimes external factors would be good for borrowers but on 19 occasions it was found to have been bad for borrowers.
"That suggests there is a real issue there," he said.
Under the banking executive accountability regime, it will require the banks to lodge with the Australian Prudential Regulation Authority a clear list mapping out who is responsible for what.
"If there is a scandal in a particular division it will be pretty clear where the buck should stop," he said.
Mr Coleman said there has been a lack of accountability and no executive has been fired over previous issues but under this new regime, APRA can issue fines of up $200 million.
