Adern confirmed a Labor staffer had spoken to New Zealand MP Chris Hipkins about Joyce's citizenship status, not an Australian MP.
That staffer was Senator Penny Wong's chief of staff Marcus Ganley, who is a New Zealander who previously worked for Helen Clark and Michael Cullen.
Wong later confirmed the contact in a press release without naming the staffer.
"A staff member in my office had informal discussions with New Zealand friends about domestic political issues, including the section 44 debate," the release read.
"At no point did he make any request to raise the issue of dual citizenship in Parliament, a fact confirmed today by Mr Hipkins and the New Zealand Labour leader."
NZ First leader Winston Peters has compared the citizenship fiasco to the infamous underarm bowling incident in a 1981 One Day cricket International between Australian and New Zealand.
The former New Zealand Foreign Minister said: "The hit put on Australian Deputy Prime Minister by the Labour Party and corroborated by a Minister in the National-led government is like an underarm delivery.
"Are Labour's Chris Hipkins and Minister Peter Dunne our answer to the Chappell brothers?
"It is distasteful to see the New Zealand Labour Party colluding with the Australian Labor Party on what was a political hit job targeting the Australian Deputy Prime Minister. More so with Minister Peter Dunne corroborating information that had obvious political intent.
"This could do serious damage to New Zealand's relationship with Australia and the rights of New Zealanders in Australia. After the foreign interns controversy, people deserve to know what other foreign sourced information is being fed into Labour here.
"This is not how we do things this side of the Tasman. Simply put, it is not cricket."
Australian allrounder Trevor Chappell's underarm delivery to Kiwi batsman Brian McKechnie led to a straining of trans-Tasman relations.
Then New Zealand Prime Minister Robert Muldoon said it was "the most disgusting incident I can recall in the history of cricket".