Ms Bennett told Parliament on Wednesday that the man at the centre of the allegations works in the Labour Leader's office at Parliament.
"These are serious allegations, the Prime Minister cannot keep her head in the sand and pretend like it is happening somewhere far, far, away, it is happening in her own office, in her own organisation, she is the leader of the Labour Party."
The Prime Minister fronted media today, saying she had accepted the resignation of Labour Party president Nigel Haworth, following a series of allegations from complainants that contradicted Haworth and his handling of the complaints.
Video courtesy of NZ Herald
Ms Bennett later named Ms Ardern's former chief of staff Mike Munro as knowing about the allegations, her chief press secretary Andrew Campbell and the director of her leader's office, Rob Salmond.
"I have been told by two victims who work in Parliament that they went to Rob Salmond around Christmas time and made a complaint about the alleged perpetrator," Ms Bennett said.
"The Prime Minister has constantly said her office did not receive complaints and in fact encouraged victims to speak to their line mangers, they did."
Ms Bennett told Parliament it all "smacks of a cover-up", and goes "straight to the top to the Prime Minister, to senior Cabinet Ministers and to senior staff in her office".
RNZ asked Mr Salmond to comment on Ms Bennett's claim - in response the Prime Minister's office issued a statement saying: "We have no comment to make on the allegations made under the protection of Parliamentary privilege".
Finance Minister Grant Robertson - also named by Ms Bennett in Parliament - has refused to answer questions about whether he was told directly of allegations of sexual assault.
He was asked if a complainant told him about such an allegation in late June this year.
"I'm going to respect the privacy of the young people who are involved in this situation, there is a process to go through with the QC, it's important the voices of these people are heard and I'm not going to say anything more about that."
Mr Robertson was also asked what has been done to ensure anyone working with, or volunteering for Labour will be safe.
"That is absolutely what we've had at the top of our minds..."
