At least five other women claim David O'Byrne has sexually harassed them since 2007, Clark independent MHA Kristie Johnston has told State Parliament under parliamentary privilege.
Ms Johnston - whose sister Rachel Midson was the subject of a sexual harassment claim and investigation regarding Mr O'Byrne - detailed further allegations which she described as "a pattern of sexually predatory behaviour".
Mr O'Byrne has resigned from Labor caucus but is continuing to serve in parliament as a Labor member for Franklin, following calls from party leader Rebecca White for him to resign from parliament.
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He has described the new allegations from Ms Johnston as "unsubstantiated".
Ms Johnston put forward a motion that called on the parliament to acknowledge that workplace sexual harassment is not inevitable or acceptable, that it is a societal issue and that a safe workplace culture must be provided.
During the subsequent debate on Tuesday, Ms Johnston outlined an accusation by two Greens volunteers of sexual harassment by Mr O'Byrne, and another from a long-term Labor supporter who claimed she had been told of other such instances.
"Other victims have reported to me that they too have tried to speak up or call out Mr O'Byrne's behaviour, but have been discouraged and told that 'that's just what David's like', 'he's handsy'," Ms Johnston said.
"I know that in some circles, women actively try to buddy up so they are not at risk of being left alone with him."
In a statement read out by Ms Johnston on behalf of the Labor supporter, Mr O'Byrne was described as "leaving a trail of victims".
Further allegations were also made about Mr O'Byrne's conduct before and during the independent investigation into his conduct against Ms Midson, undertaken by former Fair Work Commissioner Barbara Deegan.
Ms Johnston claimed Mr O'Byrne contacted potential witnesses and tried to influence evidence.
"He called in lawyers, tried to background on her, and changed his tune by saying the conduct was consensual," she said.
"In the meantime, someone within Labor told Mr O'Byrne of the complaint and its contents. Mr O'Byrne took it upon himself to contact potential witnesses for the complainant and to try to influence the evidence that they might give."
Earlier on Tuesday, at the start of question time, Mr O'Byrne read out a statement in which he called on Labor to release the Deegan report fully to himself and Ms Midson, and to others if necessary, to allay "doubts about its findings".
Rebecca White to 'redouble' efforts to give women a voice
Labor leader Rebecca White spoke on the motion from Ms Johnston, invoking Australian of the Year Grace Tame and the Brittany Higgins matter in detailing how more needed to be done to protect women in the workplace.
She said the process involving Mr O'Byrne and Ms Midson had been "traumatic" for both parties.
"We need to make sure that as a party we have a robust policy to ensure that if people have a complaint, they can raise it in confidence and it can be dealt with appropriately and they're not further traumatised by going through that experience," Ms White said.
"I will be redoubling my efforts to ensure that women are able to come forward and have their stories heard in a safe and respectful way.
"We all need to do what we can do to improve the processes around sexual assault and harassment and ensure that all women are supported so that they do not suffer any more than they already have."
She said Labor's review into the 2021 state election would look into the party's governance and was an opportunity for members to raise issues.
Her comments did not go far enough, according to Premier Peter Gutwein, who said Labor should not wait until for the election review to instigate procedural changes.
"There are five other complainants that don't feel safe or in any way supported to come forward to the Labor party, the question has to be asked: what are you going to do right now about this?" he said.
"I would encourage you as a leader of the party to not wait for a review to occur.
"I think we all understand what's missing here, and that is an independent investigatory process where people that feel aggrieved with Labor members can come forward feeling safe, feeling protected and can have those matters heard.
"And you as leader have an opportunity to put in place a process that enables them to feel protected, to feel safe, to enable a process that's independent and can be seen to be independent, and can occur. I heard none of that from the leader of the opposition in her contribution."
During his contribution, Ms White interjected to inquire whether the Liberal party itself had such processes, and raised the Adam Brooks matter as an example of their shortcomings.
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