Preliminary results from a necropsy (animal autopsy) undertaken by Department of Conservation staff and Massey University marine mammal pathologist Stuart Hunter on Wednesday showed the healthy whale had died as a result of boat strike.
Doc marine ranger Jim Fyfe said they found both jaws of the whale were broken and it had a severe gash on its head.
"The injuries did occur while it was still alive and were substantial enough to cause its death."
Examination of its reproductive system indicated its calf might only be a month or two old and, at that age, would probably not survive by itself, he said.
"We may see the calf [on a beach] in due course, so if anyone does observe anything washed up they need to report it in."
The calf would be about 2.4m to 3m long.
Doc contracted Massey to do necropsies in cases of suspicious deaths of marine mammals to confirm cause of death.
The necropsy also gave University of Otago zoology students and academics a chance to learn from the whale's death, he said.
After consultation with runanga, the whale was buried in a grave site along Otago's coast.