The stranded whale. Photo: Facebook / Project Jonah
Emergency services and other organisations will be checking on the whale stranded at a Christchurch beach at first light on Sunday.
Project Jonah said a volunteer medic was on site within six minutes of being called, when it was first made aware of the incident on Saturday night.
It is thought to be a sperm whale.
"This large whale, thought to be a sperm whale, is currently alive," a Project Jonah spokesperson said in a social media post.
"With whales of this size there are a number of logical and health and safety considerations that must be taken into decision making."
The whale was stranded on the ocean side of a sandbar which was considered too deep to walk to, especially in darkness.
High tide was due at 11pm so it had been decided not to enter the water on Saturday night.
Department of Conservation staff, Te Ngāi Tūāhuriri Rūnanga and the police were all involved in the response.
People were being asked to stay away and not to go to the beach to sightsee.
DOC staff were among those checking on the whale before darkness fell. Photo: Facebook / DOC