The body of an elephant seal was pulled from the waters of Departure Bay in Nanaimo on Saturday. (Submitted by Andrew Trites)

Scientists were looking for more clues Monday to determine what led a giant northern elephant seal into Nanaimo's Departure Bay.

The seal's massive carcass, which measured more than four metres in length and weighed 2,000 kilograms, was found floating in the harbour on the weekend.

A necropsy revealed the dead seal had many broken bones, including its backbone, suggesting it had been hit by a large ship.

Andrew Trites, director of the University of British Columbia's marine mammal research unit, said the animal has been transported to a UBC research facility in the Lower Mainland.

"It sort of defies the imagination. I think some would say it looks more like a whale than a seal. It's the largest seal in the Northern Hemisphere," he said.

Trites said it's the first time in his 28 years of work that he's heard of an elephant seal in the Georgia Strait, which separates Vancouver Island from the mainland coast.

Was nearly extinct

The elephant seal was hunted to near extinction 100 years ago and may now be returning to waters it previously inhabited, Trites said.

The animals have been observed in recent years further south at Race Rocks near Victoria, and have re-established large breeding colonies along the California coast.

But even if the animals are returning to the Georgia Strait, Trites said, don't expect to see an elephant seal anytime soon.

"The chance of people seeing this on a regular basis is very small because they are spending most of the time under water with just their head and gigantic snout coming out," he said.

Trites said he believes elephant seal sightings are the source of many sea-monster legends.

"I think if people do see them, their first reaction is they won't quite believe what they saw, in fact they won't even know what they saw, except it was something like they've never seen in their lives," he said.