Further allegations of inappropriate conduct have been raised against Senator David Van after two female parliamentarians accused him of improper sexual behaviour.

Opposition Leader Peter Dutton said he had raised an additional allegation with Senator Van in making the decision to expel him from the Liberal party room.

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

Former Liberal senator Amanda Stoker on Thursday accused Senator Van of inappropriately touching her at a 2020 event.

Asked 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.

“I believe it is in the best interests of the Liberal Party and that’s what I have acted upon and I don’t want Senator Van sitting in our party room. I have made that clear.”

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.

“It’s been an issue in the press gallery, been an issue in Parliament House and obviously … I’ve referred the matters to that independent workplace authority for investigation.”

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

“It’s such a toxic culture in that workplace, 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.

In her statement, Ms Stoker said Senator Van “inappropriately touched me at an informal social gathering in a parliamentary office” in November 2020.

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

“By its nature and by its repetition, it was not accidental.

“That action was not appropriate. It was unprofessional and uninvited.”

Senator Van said he had no recollection of the incident, telling News.com.au he had a “friendly” chat with Ms Stoker after her complaint and he would never have inappropriately touched her.

By Tess Ikonomou in Canberra