Three rare Gray's beaked whales discovered dead on Ruakaka Beach this morning will be buried at a sacred site just off the beach.

The whales stranded at high tide, possibly just before dawn, but marine mammal experts were unsure as to why they they swam close to shore as they are usually deep sea dwellers.

Orca expert Ingrid Visser, Whale Rescue's technical adviser Steve Whitehouse and Department of Conservation marine ranger Marie Jordan travelled to the site, about 2km south of the Ruakaka Surf Lifesaving Club, to determine what type of whales they were and to make arrangements for their removal.

Local iwi have given their permission for Dr Visser to perform a necropsy to determine the cause of death