Marine mammal expert Anton van Helden was sent the footage by someone at Auckland University.
He said the creature appeared to be a killer whale.
"The video pans over the flipper and it is a flat paddle shape which is diagnostic of the killer whale."
Mr van Helden said the dead whale might have been out at sea for some time before being washed up on the beach.
"It is very typical for whales of different shapes and sizes to wash up on beaches around New Zealand," he said.
He said anyone who came across whale carcasses needed to report it to the Department of Conservation.
"They are the Crown authority in these cases and they will determine if the carcass needs top go to scientists or tangata whenua."
He said he understood the remains had since been washed back out to sea.
- Rotorua Daily Post
