One Nation leader Pauline Hanson has alleged an unnamed male Senate colleague has sexually harassed a female staffer in this term of parliament.
Late in the Senate on Tuesday night, when all of the focus had been on the House of Representatives and the medevac legislation, Hanson said that a "current senator" was currently under investigation, and that taxpayers had been forced to pay out unfair dismissal cases by staffers during the senator's term.
Hanson said this applied to more than six staffers in this term of parliament alone.
"Each of those people has been gagged from speaking publicly about their experience, and I respect the decision they have made to accept those terms and remain silent," Hanson said. "But what is disappointing is that this parliament has allowed the horrible treatment of staff to continue without this senator being forced to go through some form of training to prevent the poor treatment of his employees."
The gag orders had left a "vulnerable woman" open to harassment, Hanson alleged.
"This gutless wonder we call senator should tonight hang his head in shame," she said.
"I expect the behaviour of all elected members to be honourable. What senators in this place need to understand is that our staff are no different to us.
"Just because you wear the red pin doesn't give you permission to place your unwanted hands or lips on your staff."
The Department of Finance, which bears responsibility for the staff employed by members of parliament in a non-party capacity, told the Senate late last year that since 2012 there have been seven formal complaints made from staffers of bullying and harassment by their employing member of parliament. In the last financial year, there was one formal complaint.
At the time, the department said there were no formal investigations conducted in the last financial year.