Australia’s banking regulator has been deliberating proposals to break up the big financial institutions as revelations of misconduct continue to pile up at the banking royal commission.

The Australian Prudential Regulation Authority has been considering advice on breaking up the banks, The New Daily can reveal, but is refusing to disclose details on the grounds that it relates to the regulator’s “deliberative process”.

The revelation comes after The New Daily filed a freedom of information request with the regulator for material outlining the pros and cons of proposals to separate higher-risk services, such as financial planning and insurance, from everyday banking.

APRA refused the application on the basis that documents in its possession that touch on the issue contain “opinion and advice” prepared for its deliberations, exempting them from release.

It’s unclear where the advice came from or what weight the regulator has given to it. APRA did not respond to subsequent inquiries for comment.

Calls to break up the big four banks have grown amid a flood of revelations of shady practices at the royal commission, which is scheduled to deliver its final report in February 2019. Commonwealth Bank, NAB, ANZ and Westpac have been implicated in misconduct ranging from falsifying forms to charging deceased customers and misleading the corporate regulator.

Last month, Treasurer Scott Morrison warned against committing “economic self-harm” by breaking up the banks, while announcing stiffer penalties of up to 10 years in jail for white-collar offences.

In an apparent reversal, however, Mr Morrison’s department earlier this month called on the royal commission to investigate the benefits of spinning off wealth management and other subsidiaries from the major banks.

A number of Labor figures, including assistant Treasury spokesman Matt Thistle­thwaite, have also hinted the party could support such a move in government. The Greens have called for vertical integration among banks to be investigated since the run-up to the last federal election.

Proponents of a breakup argue that separating non-core subsidiaries, such as financial advice and wealth management services, would reduce incentives for dubious financial advice and lessen systemic risk in the financial system.

“All the people in those investment banks are incentivised to put the banking aspect of it through their parent company and also to steer people toward investments where they’re going to make a buck out of it, a commission sort of arrangement,” said David Richardson, a senior research fellow at The Australia Institute. “This seems the really serious part of it.”

The royal commission could end up recommending some form of separation for the banks, Mr Richardson said.

“It will be interesting to see what the royal commission recommends and perhaps that is why APRA is working on this issue, because they suspect that the royal commissioner may recommend some sort of structural separation and trust-busting sort of stuff.”

University of Melbourne economics professor Paul Kofman, however, said such a move would also have potential downsides, including weakened financial institutions and reduced incentives to offer redress to mistreated customers.

“The big four have their reputation at stake, so are likely to compensate victims – [that’s] much less likely for small independent operators that might actually collapse and leave the victims with no recourse,” Professor Kofman said.