Forty pilot whales were buried and 10 euthanised in New Zealand after the pilot whales beached, the country's Department of Conservation (DOC) confirmed.
The whales became stranded at Whangakopikopiko Island and Bryan's Beach where the 40 whales had to be buried while the 10 euthanised whales were beached in Ohiwa.
The decision to euthanise a number of the whales was taken because of the welfare of the trapped whales and the inability to refloat the whales because of weather conditions.
The DOC said that it collected tissue samples from 49 of the whales that died on the beaches.
Incident controller Jono Maxwell said that 30 whales that had beached in Ohiwa were saved and led back out to sea.
An aircraft was sent to search for the whales but they were not located.
"They flew from Matata in the west around the off-shore islands, over all of Ohiwa harbour and east to Waihau Bay. With perfect visibility they did not see any whales or even dolphins.
"At this stage we are hopeful there will be nothing but good news for both the whales and those of our staff and the community who have rallied to support this incident.," Maxwell said.