Labor has renewed calls for a royal commission into the banking sector after reports the big four institutions have all been used by criminal groups to launder drug funds.
Up to $5 million a day is being laundered through Australia's big banks, Fairfax reports.
As well as Westpac, ANZ, NAB and CBA, crime groups have also infiltrated mid-tier institutions like the Bank of Queensland and Bendigo Bank, it says.
Labor frontbencher Anthony Albanese says the revelations are 'another argument' for a royal commission into the sector.
'We need a banking royal commission, and I don't know why the government is resisting this. It will happen, let's get on with it,' Mr Albanese told the Nine Network on Friday.
But government minister Christopher Pyne again dismissed calls for the inquiry, saying it would take 'years and years to report and to do anything'.