Thirty-six whales have been confirmed as stranded on Farewell Spit at the top of the South Island on Thursday night, and some have died.
The Department of Conservation travelled to the area to confirm the stranding.
Project Jonah said DOC rangers were on site assessing the situation and would provide another update in the morning.
They said the whales were spread along several kilometres of the beach.
Whale and dolphin strandings are common at the top of the South Island - more than 60 pilot whales needed help just last month, and 28 died.
A few years ago, 300 pilot whales died at Farewell Spit.