But the Australian Deputy Prime Minister should embrace his ''strong'' North Otago roots, and cheer for the All Blacks, John Laing, of Kakanui, says.
''Cheer for a winner,'' he said.
Mr Joyce is mired in a transtasman citizenship row after it was found he entered Australia's Parliament as a New Zealand citizen because of his father's Kiwi lineage.
And though he has confirmed he is no longer a New Zealand citizen, Mr Joyce's Kiwi roots, their potential impact on Malcolm Turnbull's majority government, and the New Zealand Labour Party's role in the saga continue to make headlines on both sides of the Ditch.
Mr Joyce and Mr Laing share a great-grandfather, 1st Class Constable Michael Joyce, who joined the Otago Armed Police in 1876 and served in Hampden for 21 years.
Their grandfather, Lieutenant-colonel John Patrick Joyce, DCM, OBE, of the Royal New Zealand Artillery, served in Gallipoli in World War 1 before rising through the ranks and helping to establish the site for the Waiouru Military Camp before returning to Hampden.
There he had four children - Frances, Patrick, Mr Laing's mother Elizabeth, and Mr Joyce's father Jim Joyce.
Mr Laing (60), the former Hampden School principal, had not seen his first cousin since childhood but had followed his political career in the news and was ''quite proud'' knowing he had done so well.
''He occasionally calls my mother, because my mother's quite elderly,'' Mr Laing said.
There were ''heaps'' of cousins and the large family was scattered over both sides of the Tasman.
He watched the citizenship news unfold with ''disbelief''.
''It's a bit of gamesmanship, isn't it?'' he said.
