Prime Minister Scott Morrison said he is "very upset" by new allegations from a second woman claiming she was assaulted by the same former Morrison adviser accused of raping Brittany Higgins in 2019.
"That's a very distressing event," he said.
The new allegations follow reports earlier this week that Ms Higgins, a former Liberal staffer, was raped by a Morrison adviser in Defence Minister Linda Reynold's office in the early hours of March 23, 2019.
Mr Morrison said he was made aware of the new allegations when they appeared in the media this morning.
"These events sicken me, they truly sicken me," he said.
"I think we've got a problem in the parliament and the workplace culture that we have to work on."
Mr Morrison said he "welcomed" a police investigation into Ms Higgins' complaints and maintained he and his office sought to have the matter dealt with as soon as they were made aware of the allegations.
Australia's Opposition Leader Anthony Albanese today described the new reports as "shocking" and "distressing".
"This has been a deeply distressing week and for Brittany Higgins she has just shown extraordinary bravery in coming forward with what happened to her two years ago," he said.
Mr Morrison has denied being aware of Ms Higgins' complaint until it made headlines on major news networks earlier this week.
Mr Albanese said it is "beyond belief" that Mr Morrison could not have been aware of the reported sexual assault.
"What we need here is honesty and transparency," he said.
In a statement released earlier this week, Ms Higgins accused Mr Morrison and other senior parliamentary staffers of failing to provide her with the necessary support following the incident.
"The continued victim-blaming rhetoric by the Prime Minister is personally very distressing to me and countless other survivors," she wrote.
"A current senior staffer to the Prime Minister and my former Chief-of-Staff refused to provide me with access to the CCTV footage from that evening and continually made me feel as if my ongoing employment would be jeopardised if I proceeded any further with the matter."
The Government has questions to answer for their own conduct."
Mr Albanese called on the Prime Minister to make public the internal review into his office's handling of the allegations at the time.
"If he doesn't, it's a complete farce," he said.