Department of Conservation operations manager Murihiku John McCarroll said it was identified as a Gray’s beaked whale, or hakurā, a species seldom seen due to its preference for deep ocean waters.
It was discovered last week morning by a member of the public out walking their dog.
Doc were notified and staff arrived on site about an hour later.
"The animal was a mature male, 4.6 metres long and had washed up dead," Mr McCarroll said.
"The overall size combined with extensive scarring on the skin suggest it was an old individual; the absence of evidence to the contrary would support a conclusion of death by natural causes."
Gray’s beaked whales are rarely observed alive, and much of what is known about them comes from stranded specimens.
The body was promptly removed from the Willsher Bay, Karoro Creek area following standard procedure, with Doc staff taking measurements and photographs before collecting biological samples.
"Local mana whenua have been consulted and expressed a preference that, once scientific samples are taken to support ongoing knowledge building and conservation, this taonga be buried as close as practicable to where originally found," he said.
Samples will be sent to research programmes at universities in Auckland and Palmerston North.
