National Party leader Judith Collins says another woman has come forward with a complaint about former National MP Andrew Falloon.
Police have reopened their original investigation into Falloon after other women either contacted the National Party, or the media.
Collins said this was at least the fifth woman and she has encouraged the latest person to go to the police.
"Knowing that there are other victims should give some comfort to those victims who have not yet decided to come forward," Collins told reporters.
"If there are more, please come forward. It's clearly a pattern of behaviour... The more women who come forward to the police, the more evidence the police will have."
Police initially investigated Falloon after reports he sent indecent pictures to the 19-year-old, but found it "did not meet the evidentiary threshold for prosecution". However, three more women came forward when news broke earlier this week.
The White Ribbon Trust has removed Falloon as an Ambassador.
Falloon's statement announcing his resignation on Monday - at that point, to take place at the election - referenced unresolved grief around three friends committing suicide when he was younger, and another friend recently taking their own life having reopened those wounds.
He said he was receiving counselling and had to put his health and wellbeing first.
The next day Collins said Falloon lied to her and the police about inappropriate sexual messages to women.
Questions are now piling up over whether Falloon used mental health as a way of deflecting from the truth.