Deputy leader Larissa Waters soon follows after learning she is a Canadian and Australian citizen.
July 21: Blogger William Summers questions whether National Party leader and Deputy PM Barnaby Joyce is a NZ citizen because his father was born in NZ.
July 28: The Australian newspaper is told by Joyce's spokesman he was not a dual citizen and had checked prior to entering Parliament. NZ's Department of Internal Affairs (DIA) tells The Australian someone needs to apply to be a citizen.
In a blog post, Summers questions that, pointing to the 1948 New Zealand Citizenship Act which indicates citizenship is automatic for anyone born to a NZ father.
August 3: Summers emails DIA to clarify the law.
August 7: Australian Fairfax reporter Adam Gartrell follows a tip-off about Joyce. Checks with Joyce's office and emails the NZ High Commission with a hypothetical question after being told they will not comment on individual cases. That is forwarded to NZ Department of Internal Affairs.
August 9: Labour MP Chris Hipkins lodges two written parliamentary questions with Internal Affairs Minister Peter Dunne.
They are:
Would a child born in Australia to a New Zealand father automatically have New Zealand citizenship?
Are children born in Australia to parents who are New Zealand citizens automatically citizens of New Zealand; if not, what process do they need to follow in order to become New Zealand citizens?
The replies are due on August 17.
August 10: DIA investigates and notifies Foreign Affairs officials and the Ministers' office late that afternoon that Barnaby may be a New Zealand citizen and should be notified. It is understood the briefing included reference to both the questions of Australian media and those of Hipkins.
Australia's High Commissioner Chris Seed notifies Joyce.
August 12-13: Joyce lodges papers to renounce citizenship.
August 14: Joyce tells Australia's Parliament he has been notified by the DIA that he may be a dual citizen. He refers it to the High Court.
Joyce says DIA looked after "inquiries from the NZ Labour Party".
Hipkins' questions are found on the Parliament website. Internal Affairs Minister Peter Dunne says DIA was prompted by media questions, rather than Hipkins.
15 August:
Morning: Hipkins admitted questions were prompted by a conversation he had with an "acquaintance" in the Australian Labor Party seeking clarification of the law.
He denied knowing the questions related to Joyce. Labour leader Jacinda Ardern says it was inappropriate for Hipkins to ask the questions but maintains he did not know it was about Joyce.
Afternoon: Australia PM Malcolm Turnbull and Foreign Minister Julie Bishop accuse ALP of colluding with NZ Labour to try to undermine the Australian Government. Bishop says a New Zealand election is coming and it will be hard to trust a future Labour Government after the week's events.
Foreign Minister Gerry Brownlee says Bishop's reaction is justified given Labour's apparent involvement and claims Hipkins questions prompted the DIA to look at the case - contrary to Dunne's claim it was the Australian media.
Ardern says Bishop's claims about Labour's involvement are false. She meets the Australian High Commissioner Peter Woolcott and says Hipkins' actions were wrong, but he was not aware it related to Joyce.
Bishop says she accepts Ardern at her word.
Joyce's application to renounce citizenship is formally accepted.
That night it is revealed Hipkin's ALP contact was Marcus Ganley - the Chief of Staff for ALP Senator Penny Wong. Ganley worked with Hipkins and Ardern as a ministerial adviser in the Labour Government.
16 August:
Wong denies any request was made for Hipkins to ask parliamentary questions on the issue.
Hipkins will not comment and Ardern said it was time to "move on".
Prime Minister Bill English says the incident will not have a lasting impact on Australia - NZ relations.
Bishop pulls back on criticising NZ Labour, but continues to claim the ALP was trying to use NZ Labour to undermine the Australian Government.
