The head of the nation's consumer watchdog has denied he is demanding a fresh banking inquiry, saying it is up to Treasurer Josh Frydenberg what investigation his agency takes up next when it comes to this sector.
But the Australian Competition and Consumer Commission chair Rod Sims is concerned about a lack of competition in the industry.
"We don't think there is strong competition in retail banking," he told a parliamentary inquiry on Wednesday.
"Even though we have got some quite big players outside of the big four, it's not clear any of them are really displacing any of the big four or making serious inroads."
He said newspaper headlines that the ACCC wanted something akin to another royal commission were incorrect.
Media reports suggested the ACCC had asked Mr Frydenberg to approve an investigation into complaints about banks stopping customers from switching institutions, while examining the levels of fees and interest rates for loyal bank customers.
Mr Sims said former treasurer and now Prime Minister Scott Morrison had previously directed the commission to investigate whether the bank levy he had imposed had been passed on to customers and to review how banks handle foreign exchange.
Those two inquiries have been completed.
He said the commission is now in discussions with Treasury and will be meeting the treasurer shortly to decide what the next one will be.
"It's just part of a sequence of inquiries that were always intended and quite what the next one is or when it will occur will come out of our discussions with the treasurer," he said.
He admitted the headlines about him requesting a new inquiry into the banks came from him "foolishly" telling journalists he was talking with the treasurer's office and the treasurer.
Even so, the body that represents financial institutions such as credit union and building societies - the Customer Owned Banking Association - would welcome a thorough investigation into competition.
"We don't have sustainable banking competition at the moment," the association's CEO Michael Lawrence said in a statement.
"A lack of competition can contribute to inappropriate conduct by firms, and insufficient choice, limited access and poor-quality products for consumers."