A six-week study by Chinese and overseas scientists two years ago revealed there was no sign of the white-fin dolphin in China, fuelling fears the fresh water dolphin - also known as baiji - is extinct.

But recently, Chinese media reported the sighting of a dead white-fin dolphin cub in Yangtze River in Anhui province. Villagers saw the carcass floating near the Tongling National Fresh Water Dolphin Nature Reserve on Sunday.

The dead cub was transported to the Yangtze aquatic animals protection center in Tongling. Staff at the center persevered the body in formalin liquid. A member of staff said the head of the dolphin had already decomposed by the time the body arrived at the center.

The dead cub was 70 to 80 centimeters in length. Experts are unable to ascertain whether it's a white-fin dolphin cub.

Senior researcher Jiang Wenhua said that researchers would need to anatomize the body to determine if it was a white-fin dolphin.

The baiji, identified by its long, teeth-filled snout and low dorsal fin, is a species of fresh water dolphin that has existed for over 20 million years.

It is the cousin of the bottlenose dolphin, which is also on the endangered species list.

Scientists from China, Japan, Britain and the United States failed to spot a white-fin dolphin during their six-week study of its natural habitat in the Yangtze River two years ago.

Some scientists said the unique species was extinct in the Yangtze River.

However, last year, three Tongling citizens recorded a short video of what looked like white-fin dolphins in the waters where the dead cub was recently found.

A research team recorded 13 mammals in the white-fin dolphin survey conducted in 1997.