Green Party co-leader Metiria Turei has confirmed the Social Development Ministry is investigating her benefit history.
She said she had been in touch with the ministry, and this afternoon said she had learned it was going to investigate her.
Earlier this month, Mrs Turei revealed she'd lied to Work and Income as a young solo mother in order to receive more benefits.
Mrs Turei said she would meet with an investigator from the Ministry next week.
She said she wrote to them on Monday, asserting her willingness to co-operate fully with an investigation into the period of time she received a benefit during the 1990s.
She said she had not taken any legal advice about the investigation and what it could mean for her role as a member of parliament.
Earlier today, she said she was not aware of an amnesty for beneficiaries at the time she lied to Work and Income in order to receive more benefits.
Mrs Turei said she wanted an amnesty for beneficiaries who have broken the law so they can come forward without fear of being punished.
Mrs Turei was on the DPB from 1993 to 1998.
But it was while she was at law school between 1995 and 1998 that she deliberately did not tell Work and Income how many flatmates were living with her, because she did not want her benefit cut.
That situation occurred in three different flats.
Mrs Turei said she did not know what the outcome of the investigation will mean for her role as a member of parliament.
"I don't know and I won't know until I've spoken to them about the consequences.
"I haven't taken any legal advice about this. It wouldn't have made any difference to my decision to go public."
Mrs Turei also revealed that she campaigned for the satirical political party, McGillicuddy Serious Party, and the Aotearoa Legalise Cannabis Party while on the benefit.
"I've been a political activist for nearly 30 years... any person, whether they're on a benefit or not, should be entitled to do that.
"I was not paid for political campaigning."
Turei shouldn't be advocating for others to break the law - PM
Prime Minister Bill English said MPs should not be advocating for others to break the law.
"Of course people make mistakes... it's the job of the police and then the justice system to take account of those circumstances because life is a bit messy."
"Mrs Turei seems to be getting a bit disconnected from the normal assumptions we make that people should kept the law," Mr English said.
Her co-leader James Shaw was not worried the fraud revelations would hurt their party's chances at September's election.
He said the issue of poverty was more important than that and that the "law is an arse" in this case.
"Met has made an extraordinary personal move," Mr Shaw said.
Labour leader Andrew Little was not ruling out Metiria Turei as a cabinet minister in any government.
"There are people who have done things before they have come into parliament that have been disclosed... it hasn't disqualified them from being in parliament.
"I'm not ruling anybody in or out of a cabinet."