Attorney-General Christian Porter has called on the Government's chief lawyer for advice on whether Peter Dutton is eligible to remain in Parliament.
Earlier this week, as speculation Mr Dutton was preparing to mount a leadership challenge was reaching fever pitch, Network Ten reported concerns about the Queensland MP's constitutional status.
Mr Dutton's register of members' interests shows he is the beneficiary of a family trust with interests in childcare centres in Queensland.
Those centres, like many around the country, receive Commonwealth subsidies.
Constitutional lawyers, including Professor Anne Twomey, suggest Mr Dutton could be under an eligibility cloud due to the ban on members and senators benefitting financially from the Commonwealth.
That rule is contained in section 44(5) of the constitution, and includes both direct and indirect financial gain.
During Question Time, the Prime Minister was peppered with questions from Labor about the reports.
"I'm advised by the Attorney-General that advice has not been sought from the Solicitor-General," Mr Turnbull said in response.
"The matter has only arisen in very recent times, we are not in possession of all of the facts relating to the arrangements between the childcare centre and the Member for Dickson's trust.
"But it is an issue of the eligibility for the Member for Dickson, he has legal advice, which I have said I have not read it."
However, Attorney-General Christian Porter has now confirmed he has asked the Government's most senior lawyer, Solicitor-General Stephen Donaghue QC for advice on the matter.
"Given that today the subject of a member's eligibility was raised in Question Time and in media reports, I determined to seek advice from the Solicitor-General on the issues raised," Mr Porter said in a statement.
Earlier this week, Mr Dutton said he had his own legal advice suggesting he was not in breach of the constitution.
If the issue was to be dealt with by the High Court, it would require the House of Representatives to vote to refer Mr Dutton's matter for judgment.
Section 44(5) is the same part of the nation's founding document that brought former South Australian senator Bob Day undone.
The High Court ordered his disqualification from the Senate last year, after ruling leasing arrangements for his Adelaide electoral office breached the constitution.
