She said this was "at least" the fifth complaint National had received about inappropriate messages from Falloon.
Falloon is one of two MPs to lose their jobs in scandal this week. The other, Iain Lees-Galloway, was sacked as a Cabinet Minister and won't stand in his electorate of Palmerston North this September. Lees-Galloway had an inappropriate relationship with a former staff for more than a year.
Ardern today said she would not be getting into any further allegations regarding Lees-Galloway.
But she said she had spoken to the ex-Minister since she announced she had sacked him yesterday.
"Essentially just as a follow up after the announcements, but not to discuss anything substantial."
She said yesterday, Lees-Galloway "lost his career in politics".
But ultimate, he accepts why it needed to happen.
Asked if she knew about any other ministerial affairs, Ardern said she: "Was not going to get drawn into other rumors or speculation".
"That is not why people elect us into Parliament."
She would not comment on the fact that a new young woman had come forward, saying they had been sent inappropriate messages by Falloon.
That, she said, was an issue for National.
Asked if she would be taking up Collins' invitation to talk about the culture of Parliament and what both parties could do to help, Ardern did not directly answer.
"We've had the Francis Review – I think there is a clear path for us to make Parliament an environment where people can have faith in what's happening here and there is a code and conduct around behaviour."
But she said mostly, "that's just common sense".
"We know what the public expect of us, now we've just got to make sure we're doing that and we display that during election periods as well.
The sex-texting MP
Earlier this week, Collins revealed that Falloon had sent pornographic messages to a young woman.
He was forced to resign, after Collins said he needed to leave now, not at the election as he had previously indicated.
She said it was clear it was a pattern of behaviour – Collins said she believes the Police will likely now look into the matter.
She said Falloon's behaviour tends to be "quite secret".
"People involved in this type of behaviour, that he's clearly indulged in, are manipulative."
She is calling for anyone else who has received inappropriate messages from Falloon to come forward.
"The more women who come forward to the police, the more evidence the police will have."
Collins said it was her hope that "any victim feels able to come forward".
She said New Zealanders are "clearly sick of people like Andrew Falloon".
Asked if the election campaign is gearing up to be a grubby one, Collins said no.
"I think we can get rid of the people out of Parliament who have been actually quite revolting in their behaviours."
She said knowing there are other victims should give some comfort to those who have "yet to decide to come forward".
On the sacking of Iain Lees-Galloway, Collins said she didn't know "what else there is" when it comes to inappropriate behaviour from Labour Ministers.
"Most people in New Zealand don't know who Iain Lees-Galloway is, they don't know who Andrew Falloon is and mostly they are saying: 'why aren't you getting back to your job of sorting out our roads'?"
Asked if she knew of any National MPs who were having extramarital affairs with staffers, Collins said she knows of none.
Falloon resigned after a young woman's parents wrote to the Prime Minister's office last week about a pornographic image the now ex-MP had sent.
That information was then passed on to National leader Judith Collins, who met with Falloon on Monday.
The now-former Rangitata MP's versions of events is that he was at a party several weeks ago and briefly left his phone unattended at a party — and acquaintances then used it to send the sexual image in question.
Collins said she believed this to be a lie.