Reports that South Australia's Attorney-General Vickie Chapman is under investigation over a potential breach of the state's corruption commission laws are an "extraordinary set of circumstances", the state opposition says.
Detectives are believed to be probing whether Ms Chapman breached legal provisions by recently revealing details of an investigation by Independent Commissioner Against Corruption Bruce Lander.
Opposition legal affairs spokesman Kyam Maher says the "law is the law" and it's not up to individuals to decide which parts of the law they abide by.
"If the attorney-general has breached a law in an act she is responsible for, that is a very, very serious thing," Mr Maher told ABC radio.
"It's an extraordinary thing for a minister to breach a law that they're responsible for."
Under SA's ICAC Act it is an offence to reveal if a person is subject to an investigation by the commissioner without Mr Lander's approval.
Earlier this year Ms Chapman released some information about one of the commissioner's inquiries, prompting him to retrospectively give his approval for her statement to be published.
But Mr Maher said legal advice it had obtained suggested such retrospective approval was not allowed under the ICAC Act.
The attorney-general has so far declined to comment on the latest developments but said previously Crown law advice was that she had not breached the act.
Australian Associated Press