A dolphin that Chinese conservationists said was extinct over a decade ago may have recently been spotted in China’s Yangtze River, according to reports. The baiji dolphin, -- once referred to as China’s “goddess of the Yangtze” --  was allegedly spotted by amateur conservationists during a seven-day search mission along the Yangtze near the city of Anqung, The Guardian reported Monday. Song Qi, leader of the expedition, told the news site that he first spotted what may have been the baiji, or white dolphin, on Oct. 4.

Qi said he saw a “white dot” surface in the water and shortly after saw another “white light” appear at the river’s surface. Qi said he saw the animal, which he believed to be the baiji, a third time swimming towards the Yangtze’s eastern bank. The amateur conservationist admitted he was not completely positive that the creature he saw in the river was the baiji, and he was not able to capture any photographs of the animal. However, local fishermen in the area told Qi that they had also seen the dolphin before and they were “100 percent certain” it was the presumed extinct baiji.

While speaking with the Sixth Tone – a new site supported by the Chinese government – Qi said that “no other creature could jump out of the Yangtze like that,” and “all the eyewitnesses – which include fishermen – felt certain it was a baiji.”

The baiji was said to be extinct in the early 2000s after swimming China’s freshwater river for 20 million years. The last time a baiji sighting was confirmed was in 2002, according to reports, and in 2006, conservationists officially declared the species functionally extinct after failing to spot one single baiji during a six-week survey mission. Overfishing, pollution and heavy boat traffic on the waterway are what environmentalist say led to the extinction of the baiji.

Despite Qi and the local fishermen’s certainty, Zoological Society of London senior research fellow Samuel Turvey told The Guardian it would take much more than just an alleged sighting to confirm that the baiji is not extinct. Not only would there need to be “robust proof” and “strong evidence” that the baiji is still around, but Turvey said researchers would also need to figure out where the dolphin has been hiding all this time. Instead of focusing on the baiji, Turvey said conservationists need to work on maintaining the Yangtze finless porpoise, which is currently a critically endangered animal.

In the United States, extinction has been on the rise for freshwater fish since 1950. Although there are no reported freshwater sources that house dolphins in the U.S., almost 57 different species and subspecies of freshwater fish have been declared extinct since 1898.