National Party leader Judith Collins says it is "very obvious" disgraced ex-MP Andrew Falloon lied to her, the police and a lot of other people about inappropriate sexual messages to women.
Yesterday it was revealed Falloon sent an indecent image - not of himself - to a 19-year-old woman. He announced he would retire at the election.
This morning he wrote to Collins and Parliament's Speaker Trevor Mallard to resign with immediate effect, after reports of the new claims emerged.
Collins said later two more women had come forward saying they were sent indecent material by Falloon.
Police had investigated the original allegation from the 19-year-old but determined it didn't meet the threshold for prosecution.
The original image has been described as pornographic and of a woman.
Collins said police told her they were "likely'' to reopen their first investigation in light of the new information and more women coming forward.
National Party leader Judith Collins speaks to media after MP Andrew Falloon resigns. Photo: RNZ / Dom Thomas
"I've also spoken to them about the safety of Andrew Falloon and they're taking the matter very seriously.''
Collins is "absolutely appalled" by what she has been hearing.
She made contact with the 19-year-old and offered to speak to her and the young woman called her this morning.
"She's very grateful the Prime Minister and I have taken seriously and dealt with the issue ... she comes across to me as a very very nice young woman who is appalled by what has happened, and so am I."
Collins was told about the incident on Saturday after the woman first wrote to the prime minister detailing what had happened.
Jacinda Ardern's chief of staff passed the correspondence on to Collins' office late on Friday, but Collins did not meet with Falloon until Monday morning.
"I've acted very quickly, I had to confront Andrew Falloon face-to-face. This is not a matter to be dealt with by email or phone calls,'' she says.
On Monday, Falloon told Collins he was being treated for serious mental health issues.
She said she had to take that seriously.
"Andrew Falloon is still a human being, and he has a family.''
"Since then his story has changed somewhat, quite significantly, more people have come forward to advise me they have also received similar communications - unwelcomed and uncalled for communications from Andrew Falloon."
Andrew Falloon with MP Gerry Brownlee (file photo) . Photo: RNZ / Nate McKinnon
Falloon was escorted to Wellington airport by chief whip Barbara Kuriger on Monday afternoon. Junior whip Matt Doocey - a mental health practitioner - took him from Chistchurch airport to his parents' home in Ashburton.
"He is now, I understand, receiving mental health assistance at a level that it needs to be and I am obviously deeply concerned for the welfare of the young women involved,'' Collins said.
Collins expects more women will come forward.
"If I've had two already into the office this morning there will be more, and I've certainly had indications from people that they know of more.''
Falloon's media statement referenced unresolved grief around three friends committing suicide when he was younger, and that another friend recently taking their own life had reopened those wounds.
He also addressed his mental health issues saying he needed to put his health and wellbeing first.
Collins said it was appropriate to be concerned about his safety and mental health.
"I know some people say you can hide behind this but I take mental health very seriously.
"If someone's sitting in my office and telling me they have a serious mental health condition for which they're receiving treatment I'll take it seriously."
During his meeting with Collins on Monday, Falloon was asked if it was an isolated incident.
Collins says it was clear Falloon had lied to her and a lot of other people about the extent of it.
Asked whether there was a culture problem in the National Party, Collins said "there are sections of society where excess alcohol use and pornography are an issue''.
"The National Party is part of society, we like any other organisation will have people who fail that test.
"The problem is we don't know always know about it until after it happens,'' she says.
Collins was planning to speak to her MPs at caucus this morning about professional behaviour.
She said she understood no other MPs knew about Falloon's behaviour.