The Hoàn Kiếm turtle (Rafetus leloii) was a controversial taxon of turtle from Southeast Asia, found in Hoàn Kiếm Lake in Hanoi, Vietnam. Although some Vietnamese biologists assert that R. leloii is a distinct species from the Yangtze giant softshell turtle Rafetus swinhoei, of which there are only three living specimens left in the world, most authorities classify it as synonymous with the latter species. If the two taxa are to be considered distinct, R. leloii may be considered extinct.

Source: https://en.wikipedia.org/wiki/Hoan_Kiem_turtle