Mr Dutton said he had raised an additional allegation with Senator Van in making the decision to expel the Victorian from the Liberal party room.

“It’s in everyone’s best interest that he resign from the parliament, and I hope he’s able to do that sooner than later,” the Liberal leader told 2GB radio on Friday.

“I think that would be an appropriate next step.”

Independent senator Lidia Thorpe on Wednesday, under parliamentary privilege, accused Senator Van of harassment and sexual assault, allegations he strongly denied.

The following day, former Liberal senator Amanda Stoker accused Senator Van of inappropriately touching her in 2020.

Senator Van has said he has no recollection of the incident and he would never have acted inappropriately towards his then-colleague.

Asked earlier on Friday if he was aware of further allegations against the now-crossbench senator, Mr Dutton replied: “Yes.”

“I raised another allegation with Senator Van, but I’m not going to comment in relation to those matters otherwise,” he told Nine’s Today program.

“I made a decision yesterday based on all of the information that was available to me … that’s a decision I don’t regret at all.”

Mr Dutton said the alleged behaviour was unacceptable.

“The thought of sexual assault against any woman in the workplace is not something that I would tolerate,” he said.

“I’ve referred the matters to that independent workplace authority for investigation.”

Senator Van said in a statement he was “utterly shattered” by the events of the past few days and was stunned his reputation could be “so wantonly savaged without due process or accountability”.

“I will fully cooperate with whatever process Mr Dutton proposes to determine these matters as quickly and fairly as possible,” he said.

“While I understand the public interest is high, I will not be making any more public statements on the allegations until a proper examination of these claims is concluded.”

Ms Stoker said Senator Van inappropriately touched her at an informal social gathering at a parliamentary office in November 2020.

“He did so by squeezing my bottom twice,” she said.

Senator Thorpe said the past 48 hours had been horrible and parliament was not a safe workplace for women.

“It’s such a toxic culture … I’ve never experienced such a toxic workplace culture towards women,” she told ABC Radio.

“I had a media pile-on that day and it wasn’t until a white woman stood up and said ‘yeah, this happened to me too’ that the media took notice.”

Senator Thorpe said the case exemplified why women did not speak out against improper behaviour.

“I was not believed, I was questioned, I was absolutely demonised that day, by everybody,” she said.