Former parliamentary speaker Josh Teague is South Australia's acting attorney-general, replacing Vickie Chapman who has stood aside while facing an ombudsman's inquiry.
Mr Teague was sworn in as planning and local government minister on Tuesday, taking over Ms Chapman's other portfolios.
While in an administrative proclamation he also took on the functions and powers of the attorney-general.
"I feel very honoured and very conscious of this responsibility," he told reporters after the ceremony.
Ms Chapman technically remains in the Liberal ministry but has no responsibilities, will not take part in cabinet meetings and will forgo the extra pay ministers usually receive.
Premier Steven Marshall said her replacement as deputy premier would be decided at a Liberal party room meeting on Thursday.
However, the South Australian Government Gazette, published on Tuesday, indicated Energy and Mining Minister Dan van Holst Pellekaan had been appointed to the deputy position.
Ms Chapman stood aside on Monday amid ongoing conflict of interest claims and a no-confidence motion in parliament last week.
The motion came after a parliamentary committee found she had, on at least three occasions, misled the house over a Kangaroo Island development.
Despite repeatedly maintaining she had done nothing wrong, Ms Chapman said she would stand aside to allow SA Ombudsman Wayne Lines to conduct an "independent" investigation into her rejection in August of the application to build a $40 million port on the island's north coast.
It was recently revealed her family owned property near a timber plantation that would have been logged and trucked to the proposed port.
"I maintain that I have made the right decision in respect of the KI seaport proposal and that I had no conflict of interest, actual or perceived," she said in a statement.
Mr Marshall "very reluctantly" accepted Ms Chapman's decision to stand aside and said the choice of the new attorney-general was a reasonably easy one given Mr Teague's background as a lawyer.
The premier said while he did not want to pre-judge the ombudsman's report, Ms Chapman continued to have his full support and he looked forward to her returning to cabinet.
"I've looked at all of the evidence presented to the select committee but it doesn't move me one single solitary inch from the position that I've always had," he said.
"I strongly support Vickie Chapman."