David Kirk, the only All Blacks captain to hold high the Rugby World Cup in victory, changed teams on Monday when he became an Australian citizen.

But Kirk, who was chief executive of Fairfax Media for three years until he was forced out last December, has not given up his New Zealand citizenship.

"We've lived here as a family for 10 years. My children have grown up here, particularly the younger one," Kirk told New Zealand television.

"And it just seemed like the right time."

But he said his heart still belonged to New Zealand.

"I grew up in New Zealand. My heart, my emotion, my commitment of course is to New Zealand."

And Kirk, skipper of the World Cup winners in the inaugural 1987 tournament, confirmed he would always back the All Blacks over the Wallabies.

"It's the All Blacks all the way."

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