Forty-nine pilot whales died after a mass stranding at a remote beach on Farewell Spit, at the top of New Zealand's South Island, the Department of Conservation announced on Sunday.
Eight of the whales died within a few hours of the pod being stranded on Saturday and the others had to be shot because the sea was too rough and the site too remote to launch a rescue operation, officials said.
A department spokesman told Radio New Zealand the whales were not thought to be from the same pod that stranded on Puponga Beach, near Farewell Spit, before Christmas.
The latest stranding occurred at low tide about one kilometre from shore and the whales were spread over six hectares.
Department spokesperson Greg Napp said it would have been too dangerous to try to refloat the whales as anyone who lost their footing may have been swept out to sea.