Mystery surrounds a mass stranding which has left around 100 whales and dolphins dead on a remote set of islands.
Officials said 97 pilot whales and three bottlenose dolphins were discovered on the Chatham Islands, New Zealand.
Most of them were stranded during the weekend.
But rescue efforts have been hampered by the remote location of the islands, which lie nearly 500miles off the country’s east coast.
Rescuers found just 26 of the whales were still alive.
The giant mammals were euthanised in a bid to stave off great white sharks from trying to feast on their carcasses.
New Zealand's Department of Conservation (DOC) said it was notified of the incident on Sunday.
Jemma Welch, a DOC biodiversity ranger, said: "Only 26 of the whales were still alive at this point, the majority of them appearing very weak, and were euthanised due to
the rough sea conditions and almost certainty of there being great white sharks in the water which are brought in by a stranding like this.”
Mass strandings are reasonably common on the Chatham Islands, with up to 1,000 pilot whales dying in a single stranding in 1918.
Every year, up to 2,000 animals beach themselves around the world.
But marine biologists have been puzzled for years over why it happens.
Changes in ocean temperature and high-powered sonar have both been blamed.
In late September, several hundred whales died in shallow waters off the Australian coast in one of the world's biggest mass whale strandings.
An initial group of some 270 pilot whales were found stranded near the remote town of Strahan on the island of Tasmania.
But a second group of 200 then beached themselves six miles further down the coast.