Andrew Falloon's behaviour does not speak to a wider problem in the National party, its MPs say.
It has been two weeks of disarray for the Opposition with high profile resignations, a sudden leadership change and now an MP quitting after sending inappropriate sexual messages.
Rangitata MP Andrew Falloon resigned today - effective immediately - after mounting pressure over inappropriate messages he had sent to young women and whether he had been upfront with his leader and police about the extent of it.
Police have this afternoon confirmed they were once again looking into allegations brought to their attention by National Party leader Judith Collins.
"We are now seeking more information in relation to these matters," they said.
Police initially investigated Falloon after reports he sent indecent pictures to a 19-year-old woman, but found it "did not meet the evidentiary threshold for prosecution". However, three more women have since come forward.
The White Ribbon Trust has removed Falloon as an Ambassador as of Monday night, and a letter was sent to him this morning.
Questions are now piling up over whether Falloon used mental health as a way of deflecting from the truth.
Falloon's statement yesterday announcing his resignation - 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 party's mental health spokesperson Matthew Doocey said he believed Falloon had been under serious stress and grief, but that would not save him from the consequences of his actions.
Doocey - a mental health practitioner - met Falloon at Christchurch airport following his meeting with leader Judith Collins in Wellington on Monday morning, and drove Falloon to his parents' home in Ashburton.
"He was clearly upset, I have some real concerns for Andrew's mental health and wellbeing and I think it's right that he's got his wife and his family around him.''
Doocey said he was not aware of the full extent of Falloon's behaviour when he drove him to Ashburton.
"Now I know, it was completely inappropriate. I have real concerns for the young lady but also I have real concerns for Andrew's mental health and his parents and his wife.''
He said Falloon had undertaken "risky inappropriate behaviour'' but that it didn't "save him from the consequences" of it.
During the car trip to Ashburton, Doocey said Falloon reflected on being concerned for his wife and parents and the community he had served.
"He reflected on some real stress and pressure that he'd been put under in the last few weeks.''
National MP Chris Bishop described Falloon's behaviour as "appalling'' and said it was a "tough time for the National party''.
He said this was a mistake made by one MP, not the whole caucus.
"I don't think it reflects on the rest of the team, it reflects on him and he's accounted for that.''
Bishop said he was completely unaware of the situation until it broke in the media.
He said there was a well-known heavy drinking culture at Parliament, but he did not think the National Party had a drinking problem.
National MP Mark Mitchell said the caucus was still a strong team and "we've had some weak players we've had to move on and we've done that''.
Asked about the candidate selection process and how MPs like Falloon ended up in Parliament, Mitchell says, "I honestly don't know whether people get carried away with their own sense of self-importance or hubris, but that sort of behaviour does tarnish all of us and we have to identify it and stamp it out immediately''.
National MP Louise Upston described Falloon's behaviour as unacceptable and said he had done the right thing by resigning.