A complaint has been made to Parliamentary Service against the person at the centre of the Labour Party staffer allegations.
It was made by a person who does not work at Parliament, meaning Parliamentary Service cannot act on it.
Parliamentary Service employs the staff who work at Parliament.
It comes after an open letter sent by some of the alleged victims of a Labour Party staffer asked for the Prime Minister to "do the right thing".
"All of us have watched in horror as this story has unfolded, as the survivors have been repeatedly re-traumatised," the letter reads.
Earlier this year, Labour began investigating after seven people made complaints against the staffer. Three months later, he was cleared.
In August, the Prime Minister ordered a review by a QC after complaints about the process.
Following an article this week in The Spinoff, in which claims surfaced from a woman who said she raised a sexual assault allegation with the investigation, the QC will now look at the whole investigation.
The Prime Minister maintained she was never told by the party or its president, Nigel Haworth, that any of the complaints were of a sexual nature.
A statement released by Mr Haworth this afternoon said the "serious allegation of sexual assault ... was not provided to the president and acting general secretary at a meeting in the Wellington Central Library or subsequently to the Labour Party Investigation Panel".
Mr Haworth said he would consider his position as Labour Party president if he is found at fault after the QC report.
National's Paula Bennett says the alleged victims feel abandoned by Labour, instead going to her.
The QC report may be completed in a matter of weeks.