Prime Minister Scott Morrison has refused to put a timeline on a decision over former attorney-general Christian Porter's future in cabinet.
Mr Porter revealed earlier this week that he'd accepted money from a blind trust to help cover legal fees for a defamation case against the ABC.
Mr Morrison is seeking advice over whether receiving the payment breached ministerial standards.
Asked whether Mr Porter would be dumped from cabinet, the prime minister told 2GB radio: "It's a serious issue."
"That's why I'm taking it very seriously and acting carefully and taking the advice on what this means for the standards and the guidelines."
But he said no time frame was linked to a decision as he prepares to travel to the United States to meet with US President Joe Biden.
Labor is demanding Mr Porter be sacked from the ministry.
Opposition Leader Anthony Albanese argues accepting money from unknown sources makes his job untenable.
"There is such a stench around this and around Christian Porter. All that is missing is a cloud of blowflies. This stinks," Mr Albanese said.
Mr Morrison refused to speculate on the now industry minister's future.
"These are not ordinary arrangements and that's why we're seeking to have a full understanding of them," he told ABC radio.
On his register of interests, Mr Porter said he had no access to information about the conduct and funding of the trust.
He sued the ABC in March over a story that revealed a now-deceased woman's historical rape allegation against a cabinet minister.
Mr Porter emphatically denied the allegation and the case was settled before trial.
Australian Associated Press