He also said he perceived broader problems with the "workplace culture" that exists in Parliament House that must improve.

But the opposition leader has slammed the government for treating Ms Higgins' assault as a "political problem" rather than a criminal offence and appointing Mr Morrison's former chief of staff to lead a review.

Ms Higgins on Friday said she was proceeding with a formal complaint to federal police over the alleged rape, which occurred in early 2019 inside the office of now-Defence Minister Linda Reynolds.

Ms Higgins has, since the incident, resigned from her job as a Liberal staffer.

Mr Morrison on Saturday said reports in The Australian that a second woman was allegedly assaulted by the same man in late 2020 - a former government advisor - were upsetting.

The woman argued that if the government had adequately dealt with the incident involving Ms Higgins in 2019, her assault would never have occurred.

But Mr Morrison insisted all ministers and political staffers who had knowledge of Mr Higgins' alleged rape sought to refer the matter to police.

He also welcomed the referral of Ms Higgins' complaint to police.

"At all times, the ministers who had knowledge of this matter and those in a senior position, the staff that had knowledge of those matters in those offices, sought to have the matter fully investigated by the police," Mr Morrison said.

"That is not something the government cannot force, we cannot do that ... as a result, it has always been our position to encourage that."

Mr Morrison claims his office did not find out about the incident at Parliament House until last week and he was not informed until Monday.

But a text message exchange between Ms Higgins and a fellow Liberal staffer within a fortnight of the incident calls this account into question.

In the message, the Liberal staffer said he had spoken directly with a member of Mr Morrison's staff. Ms Higgins this week said at least three of Mr Morrison's staff had prior knowledge of the incident.

Mr Morrison's former chief of staff, the current Department of Prime Minister and Cabinet secretary Phil Gaetjens, has been tasked with leading a review into departmental communications regarding the incident.

But Opposition Leader Anthony Albanese on Saturday criticised the appointment of Mr Gaetjens, saying the review would not be independent.

He said it was clear that Ms Higgins was "made to feel there would be consequences for her career if she pursued this matter".

"You need that arm's length capacity to deal with these issues, independent of government or any political party, to deal with it transparently and it needs to have the authority to deal with it," Mr Albanese told reporters.

"We know violence against women and children is a scourge, it is prevalent in all areas of society, but the parliament of Australia should be setting an example ... we should be an institution people can look to for best practice."

Ms Higgins has also demanded a review into the conditions under which ministerial and parliamentary staff are employed.

"Political advisers have very few protections, resources and confidential reporting mechanisms to address any workplace issues," she said.

Mr Morrison agreed cultural changes must be implemented.

"What I must do and continue to do is focus on ensuring that the needs of our staff are addressed, that they are safe, that those who have suffered the trauma and horror of events like this in the past are respected and that we give every support we can to ensure that the police authorities can take up these matters as discreetly as they possibly can," he said.

Australian Associated Press