Massey University researchers have taken tissue samples from three rare Gray's beaked whales found dead on Ruakaka beach in order to study their lifestyle.
Emma Beatson and Catherine Lea took tissue samples from the mammals to assess their lifestyle and contents from their stomach for dietary assessment.
The whales stranded last Wednesday and were buried nearby.
Karen Stockin, director of Coastal-Marine Research Group at the university's Institute of Natural and Mathematical Sciences, said the taking of tissue samples must not be confused with a necropsy or a post-mortem examination.
She said the university was not asked by the Department of Conservation to conduct a necropsy.