Ships near southern New Zealand have been warned of icebergs after several - some bigger than houses - were reported within 76 kilometres of the coast.
One iceberg, reported by a fishing boat to be 200 metres long and 50m high, was headed toward the South Island's east coast, Maritime New Zealand senior adviser Steve Corbett said.
Others, said to be about the size of houses, were drifting nearby. They were among about 100 spotted south of New Zealand on November 3, being pushed north by winds and ocean currents.
A maritime navigation warning was issued at the time.
Scientists had said earlier that it was not unusual to see icebergs so far from the Antarctic coastal region, where they had broken off the ice shelf - but that they were expected to melt as they drifted toward New Zealand.
Oceanographer Mike Williams said winds from a series of southern storms had probably driven some of the icebergs close to the South Island.
"They're surviving a bit longer than I initially expected and some of them have taken a different route than I initially expected.
"It's highlighted that trying to forecast what icebergs do is actually very, very hard."
It was likely the iceberg seen moving toward the east coast would soon be visible from land, and given its size "it should survive for a while", Mr Williams said.
Marine radio operator John McLellan said ships in the area should have been given accurate information about the icebergs much earlier.
I think this is an attempt by our trans Tasman neighbours to expand their empire. I'm not sure that it's going to work but as usual, global warming is being blamed, but this is not an uncommon thing. This has happened many times over the decades.