A senior public servant says former prime minister Scott Morrison may have breached the principles of cabinet confidence when briefing journalists during the COVID pandemic.
The Attorney-General's Department will consider an investigation into a book that revealed Mr Morrison secretly appointed himself to five ministries early in the pandemic.
Earlier this year, a book titled Plague prompted a political scandal when it revealed how Mr Morrison appointed himself to the ministries without the knowledge of his colleagues.
The Department of Prime Minister and Cabinet's John Reid on Friday told Senate estimates that it did not know Mr Morrison was briefing the book's authors, or other journalists, about cabinet matters.
Mr Reid, the department's first assistant secretary, said the book contains information that would usually be protected by cabinet confidentiality, like deliberations of the National Security Committee.
Mr Reid says the book has been referred to the Attorney-General's Department for further investigation.
"Our conclusions were that it certainly appears to reveal information that was, until revealed, cabinet material, and would ordinarily have been respected or protected under the principles of cabinet confidentiality," Mr Reid said.
He said the Attorney-General's Department will consider if further action is required.
In August, Mr Albanese commissioned former High Court justice Virginia Bell to lead an inquiry into Mr Morrison's secret ministries.
The inquiry will examine how the appointments were made and the implications arising from them.
It will also make recommendations on any changes to provide greater transparency and accountability to ensure secret appointments can't happen again.
The government is expected to receive Ms Bell's report in late November.
Before calling that inquiry, Mr Albanese received legal advice from the nation's second law officer on the secret appointments.
Solicitor-General Stephen Donaghue found Mr Morrison was validly appointed to the resources portfolio but not notifying ministers, parliament or the public "fundamentally undermined" the principles of responsible government.
In August, Mr Morrison defended the move, explaining that it was done to establish a backup to other ministers at the high of the pandemic.
"We were dealing with an incredible amount of discretion and money being paid," Mr Morrison said.
