Home Affairs Minister Peter Dutton has joined the growing list of people who knew of an alleged rape in Parliament House before Scott Morrison.
As Brittany Higgins reinstated her complaint to police over the 2019 incident, more details emerged about the knowledge of senior government ministers.
Mr Dutton confirmed Australian Federal Police commissioner Reece Kershaw informed him about the alleged sexual assault on February 11, four days before the prime minister says he was told.
Mr Morrison said his office first knew of the allegation on February 12 but took almost three days to notify him.
Department of Prime Minister and Cabinet secretary Philip Gaetjens, who is Mr Morrison's former chief of staff, is investigating if senior staff were aware earlier.
Ms Higgins is adamant a key Morrison adviser "checked in" with her via WhatsApp after Four Corners ran an expose on parliamentary culture in 2020.
The man accused of the rape was sacked over a security breach for entering Parliament House on the night of the incident.
At least two other staff now in the prime minister's office were involved in handling the security breach in 2019.
Employment Minister Michaelia Cash first spoke with Ms Higgins about the alleged rape on February 5 this year.
Defence Minister Linda Reynolds on Wednesday took medical leave after being under intense pressure over her handling of the complaint.
Senator Reynolds, who was Ms Higgins' employer at the time of the incident, says she didn't tell the prime minister out of respect for her former staffer's privacy.
The minister was due to face questions at the National Press Club but cancelled after being admitted to Canberra Hospital following advice from her cardiologist.
She has been forced to correct the record as to how many times she met with police about the allegations in 2019.
House of Representatives Speaker Tony Smith and Senate President Scott Ryan were told in 2019 about an incident at Parliament House.
They were aware federal police may request CCTV footage concerning an alleged sexual assault but later learnt no complaint was being proceeded with and did not tell the prime minister.
Mr Morrison has rejected suggestions there is a "don't ask, don't tell" culture within the government.
"I have been open about what is a very sensitive matter, a truly very sensitive and serious matter," he told parliament on Wednesday.
He said a range of actions were being taken to address cultural issues in federal politics and ensuring staff had adequate support.
Ms Higgins coming forward led to three other women saying they were also assaulted by the man.
The former media adviser says she originally felt pressured not to pursue an investigation, fearing her job would be jeopardised.
There are four inquiries stemming from the allegations, which have rocked federal parliament over the past 10 days.
Australian Associated Press