Reports have surfaced that there has been a recent sighting of a baiji, or Yangtze River dolphin, a creature declared “functionally extinct” 10 years ago. The cetacean was apparently spotted last week, as a group of amateur conservationists spent a week surveying a stretch of the river in the hope that the dolphins (Lipotes vexillifer) may still be clinging on.

The group says that they saw the dolphin multiple times, although none were able to get any photographic evidence. “I saw most of the body, and the second time around I saw its mouth and head,” the leader of the expedition Song Qi told the Chinese state news agency Sixth Tone. “The front boat saw it three times.” The creatures were declared extinct in 2006 after a six-week expedition of 30 scientists scoured the 6,300-kilometer (3,915 miles) river and found nothing.

What is thought to have been the main driver of the dolphin’s demise is the continued construction of dams along much of the Yangtze, with the building of the Three Gorges Dam being a particularly heavily blow to the species.

But in addition to that, the plethora of heavy industry and development that has sprung up along the length of the river has caused a massive increase in traffic on the water, which harms the dolphins through boat strikes and noise pollution, in addition to the masses of pollution and chemicals that drain into it. The cetaceans have also been targeted for their meat.

The combination of these deadly factors has meant that the dolphin, which had been living in the Yangtze for at least 20 million years, is no more. One of just four dolphin species to have made fresh water rivers their exclusive habitats (the others being the Amazon, Ganges, and Indus River dolphins), the loss of the baiji was the loss of one of the world’s most evolutionarily distinct animals.

This isn’t actually the first time since the baiji was declared functionally extinct that apparent sightings have surfaced. Just a year after they were listed as extinct a sighting emerged of the dolphin, but this was later proven to likely to have been that of another rare cetacean that clings on in parts of the Yangtze River, the finless porpoise (Neophocaena phocaenoides). About half the size of the baiji, the finless porpoise is a similar color and easily mistaken for the dolphin.

With little to go on apart from the eyewitness accounts, some suspect that this latest spotting may once again turn out to be a mistaken identity, although according to reports researchers arrived on the scene to help with the search to no avail. But even if the creature spotted does turn out to be a genuine Yangtze River dolphin, it’s unlikely to change the creature’s fortunes. In 2006 the dolphins were declared “functionally extinct”, which means that they may well be persisting, but if they are there are too few of them for the species to survive.