New Zealand Rugby says a hotel room where the All Blacks held meetings in Sydney was bugged before a match against Australia.
The New Zealand Herald reported that a “sophisticated” listening device found on Monday had been hidden in a chair.
The All Blacks are due to play Australia’s Wallabies on Saturday.
The CEO of New Zealand Rugby, Steve Tew, said in a statement that Australian police and the Australian Rugby Union (ARU) had been informed.
He said: “We are taking this issue very seriously, and given it will be a police matter, it would not be prudent to go into further details.”
The head of the ARU, Bill Pulver, told the New Zealand Herald that the idea of a bugging was “ludicrous”.
He said: “Mate, of course [the ARU is not involved].
“I just think it’s a ludicrous concept that there are listening devices being placed in team rooms. I don’t know how that could happen.”
The paper reports that hiding the bug “was a highly skilled and meticulous act and whoever put it there would have needed a significant amount of time to have pulled off such an accomplished job”.
Indications are that the device was working and would have transmitted conversations about the All Blacks’ strategy for Saturday’s match.
Saturday’s game is the first of three in the annual Bledisloe Cup between Australia and New Zealand. It is the only match in this year’s tournament scheduled to take place on Australian soil; the other two games are scheduled to be held in New Zealand cities. The All Blacks have won the Cup 43 times while the Wallabies have won 12 times.
Sydney police told the BBC they were not yet ready to comment.
The hotel where the All Blacks were staying has started its own investigation into the incident, the statement by New Zealand Rugby said.