A 327-kilogram (720 pound) leatherback turtle that died after swimming up Nova Scotia's Shubenacadie River was severely emaciated and likely died of starvation, an examination has revealed.

The turtle's remains were taken to the Atlantic Veterinary College for a necropsy, where experts examined the carcass to figure out why the turtle swam so far into fresh water. The investgation continues.

The turtle was about 20 kilometres up the river, a long way from the salt water, in which it needs to live.

The nearest body of salt water is the Bay of Fundy.

A local, who had been trying to help it along, spotted the animal Friday.

More locals joined the rescue effort Saturday when it was spotted again, pouring water on it to keep it hydrated before it died.

Bernadette Matthews was one of the residents who tried to keep it alive.

The turtle was 327-kilogram (720 pound) was severely emaciated and likely died of starvation, an examination has revealed. (CBC)

"I wish we could have done more, but it was an amazing experience and all my children got to see him and it was a once in a life time experience," she said.

On Sunday, officials from the Department of Fisheries and Oceans removed the animal from a mud flat, using a winch, ropes and chains.

A male leatherback turtle can reach a weight of 900 kilograms — about 2,000 pounds — according to DFO.

This turtle was very much underweight, according to Kathleen Martin of the Canadian Sea Turtle Network. A turtle with a shell its size should have weighed 450 kilograms, or 1,000 pounds, she said.

Leatherbacks are the largest reptile in the world, and are designated as an endangered species under the International Union for Conservation of Nature.

The Canadian Sea Turtle Network Initiative says the waters off Canada's East Coast support the highest concentration of leatherback sea turtles in the north Atlantic Ocean.

They're sometimes seen at the ocean's surface hunting for jellyfish.