Mr Morrison insists he is doing what he can to make the building a safer place to work.

Brittany Higgins says she was sexually assaulted by a male colleague inside minister Linda Reynolds' office in 2019.

Senator Reynolds has known about the alleged rape for more than two years but did not inform the prime minister to respect Ms Higgins' privacy and welfare.

The Australian Federal Police confirmed on Thursday a senior AFP member - described by the prime minister in parliament as an assistant commissioner - had met with Senator Reynolds and her chief of staff on April 4, 2019 "in relation to allegations of sexual assault in the minister's office on March 23, 2019".

Ms Higgins was not present at the meeting.

"The AFP has engaged with the Department of Parliamentary Services and Presiding Officers (the House Speaker and Senate President) a number of times," the AFP said.

"The matter is an open investigation and further commentary could be prejudicial."

Mr Morrison said he did not want to add to Ms Higgins' stress after she accused him of victim-blaming in response to her complaint.

"I am very sorry she feels that way," he told parliament on Thursday.

"She must be under tremendous stress over the course of this week. She has shown great courage and great bravery in speaking up."

An independent review into the workplaces of parliamentarians and their staff has been launched, and counsellors will soon be made available at Parliament House.

Mr Morrison has publicly admonished Senator Reynolds for failing to tell him, and senior cabinet colleagues are distancing themselves from the minister.

Senator Reynolds on Thursday provided another statement to the Senate, showing emotion as she recounted what happened and when.

The minister says she became aware of the alleged rape "incrementally over a period of days" after March 26, when Ms Higgins and another former staffer were called into her office.

The pair had allegedly gained unauthorised access to the minister's office - which Ms Higgins said was when the rape occurred - and the meeting related to that breach.

Senator Reynolds said she met with Ms Higgins again on April 1 to let her know she could speak to police if she wanted to pursue a complaint.

Ms Higgins has said she felt pressure to choose between reporting the matter to police and keeping her job.

Senator Reynolds has apologised.

"At the time this was a difficult, it was a complex, and it was a highly sensitive matter," she said.

"At all times, to me, Brittany's welfare and her right to privacy were paramount to me. To my part I am deeply sorry that Brittany felt unsupported at the time of the incident and in the months that followed, and in fact the years that followed."

The prime minister also remains under scrutiny over what he knew about the allegations, given at least two of his staff were involved in handling the staffer's complaint.

Labor frontbencher Tanya Plibersek has applauded Ms Higgins for speaking out.

"Your bravery will give other women courage and make this a safer workplace for all," she told parliament.

Australian Associated Press