The New Zealand First MP Brendan Horan has been expelled unceremoniously from the party caucus, and has been urged by the leader to quit Parliament altogether.
The leader, Winston Peters, made a statement to Parliament on Tuesday afternoon saying he had lost all confidence in the list MP.
Mr Peters told the House Mr Horan was given every opportunity to clear his name.
Mr Horan earlier released a statement through his lawyer, denying any wrongdoing in response to allegations relating to his late mother's finances.
He said he completely denies any suggestion he's stolen from his mother or misappropriated her money or assets.
Mr Peters said he'd requested information from Mr Horan and the people who'd made the allegations but, up until a few days ago, had received no material.
"However, substantive material has now come into my possession - some as recent as 2.15pm this afternoon - and the information we have received leaves me in a position where I have no confidence in Mr Horan's ability to continue as a member of Parliament and he will be expelled from the New Zealand First caucus forthwith." Mr Peters said.
"Mr Horan has a duty, I believe, to resign as a member of Parliament."
Mr Peters said afterwards he can't go into any more details outside of Parliament, without the legal protection of privilege.
Horan 'surprised' by expulsion
Mr Horan is currently absent from Parliament as he sorts out what he earlier described as personal and private matters.
On Tuesday, through lawyer Paul Mabey QC, Mr Horan said he has been the subject of unfair and unwarranted publicity that implied he is dishonest and stole from his mother.
He says his only wish is that the issues concerning his mother's estate are resolved quickly and properly.
On Tuesday evening, Mr Mabey told Radio New Zealand's Checkpoint programme Mr Horan is surprised by the expulsion and intends to remain in Parliament.
"He's a man who says certain members of my family are making allegations; they're not true; they've not been proven; I don't know what they are other than what I read; and now my leader has expelled me. So the combination of all of this is pretty stressful, and I think that he's feeling it."
He says Mr Horan would welcome any inquiry and wants to put the matter behind him.