A scientist from the National Institute of Water and Atmospheric Research (Niwa) has dismissed a report of an iceberg about 30km southeast of Stewart Island.

Australian Antarctic Division glaciologist Dr Neal Young said yesterday he had detected an iceberg in that position using satellite technology, in images taken about 12.30pm.

The report prompted Helicopters Otago to fly over the area, finding the reported iceberg was actually an underwater reef.

Niwa scientist Michael Williams confirmed that the image was a reef.

He had not looked at satellite images from yesterday afternoon, but images taken yesterday morning “didn’t show anything”.

The closest iceberg to New Zealand was about 240km from Invercargill, Dr Williams said.

Stewart Island Helicopters managing director Jason Wright said he had heard reports of an iceberg nearing Stewart Island, but had not seen it himself.

Weather was too poor to fly over the area and check this morning, he said.

Meanwhile, an iceberg which had split in half near Macquarie Island, about halfway between New Zealand and Antarctica, was slowly drifting north, a polar travel company said yesterday.

Read the New Zealand Herald’s full article here