"There's a possibility they'll come to New Zealand, but people shouldn't get their hopes up," Dr Williams cautioned yesterday.
Over the next fortnight, he would study satellite images and other data to try to determine more accurately where the icebergs were headed.
The mass of icebergs was drifting north from the Antarctic, past the subantarctic Macquarie Island, about 1500km southeast of Tasmania, the Australian Antarctic Division said in a statement during the weekend.
At least four icebergs have recently been spotted off the east and west coasts of the island, ranging in size from 50m to an estimated 2km in length.
A 500m long iceberg had also been sighted late last week.
The acting station leader on Macquarie Island, Cyril Munro, said the icebergs were likely to continue heading to the north and east in the general direction of New Zealand.
Another scientist said there appeared to be at least 20 icebergs around the island.
Satellite images showed a whole group of icebergs, spread over an area of 1000km by 700km, moving away from the Antarctic, he said.
Dr Williams, an oceanographer with the National Institute of Water and Atmospheric Research, said the icebergs were still a considerable distance away from New Zealand, and they could drift east into the Pacific before reaching the mainland.
At a similar stage in 2006, icebergs had initially been spotted in the Auckland Island area, which was considerably closer to the New Zealand mainland.
Dr Williams was the co-leader of a scientific research project which has recently investigated the Antarctic circumpolar current, a major ocean current which runs around the Antarctic.
That study had added to his caution about the potential route of the icebergs.
It showed that parts of the circumpolar current were more variable in strength than previously thought.
Currents moving between undersea peaks in the Macquarie Ridge, which extended from Macquarie Island to Fiordland, created further complexities, as did the effect of wind on individual icebergs, he said.
