"It's not unusual to have whales washed up on the beaches on the West Coast - we do get anything between a couple and half a dozen a year of various species," he said.
"But when they come up one after the other, it's a little bit less usual."
Mr Neale said it was unlikely the deaths were directly connected, and they could be a coincidence.
Big storms had lashed the coast last weekend, which may have thrown the whales around and led to their deaths.
The whales had been be inspected and photographed, but there were no obvious signs of ship strike or other external injuries.
"We don't know at this stage what the cause of death is, and it's possible we may never know entirely what caused their death."
Local iwi Te Runanga o Ngati Waewae had been notified and was working to recover the jawbone from the sperm whale.
The carcasses would either be buried or left to decompose on the beach.
Mr Neale reminded people not to touch the whale carcasses, and to report any sick or dead marine mammals to conservation staff.
"We don't mind people coming along and having a look at the whales, but especially with the sperm whale being worked on down there, it would be really good for people to keep their distance."
