The president of the New Zealand Labour Party has denied knowing anything about inquiries made by his party into the citizenship of Deputy Prime Minister Barnaby Joyce.
Mr Joyce told parliament on Monday the New Zealand High Commission contacted him last Thursday with the "shocking" information that he could be a Kiwi by descent.
Mr Joyce's father was born in New Zealand.
"On the basis of preliminary advice from their Department of Internal Affairs - which had received inquiries from the New Zealand Labour Party - they considered I may be a citizen by descent of New Zealand," Mr Joyce said.
It's understood the issue stems from a question on notice by Labour MP Chris Hipkins, who is Shadow Leader of the House.
In a written question to Internal Affairs Minister Peter Dunne, Mr Hipkins questioned whether a child born in Australia to a New Zealand father would automatically have New Zealand citizenship.
The response from Mr Dunne is due on Thursday.
Labour Party president Nigel Haworth told AAP he knew nothing of those inquiries.
"I have absolutely no knowledge of that at all," he said.
"I genuinely know nothing about that."
Mr Hipkins has been contacted by AAP.
Under section 44 of the constitution, anyone who holds dual citizenship is ineligible to sit in parliament.
Mr Joyce is the fifth Australian MP to have their citizenship questioned since last month, following senators Scott Ludlam, Larissa Waters, Matthew Canavan and Malcolm Roberts.
