Media reports Monday said the 1.2-meter (four foot), five-kilogram (11 pound) croc was thought to have been dumped by a pet owner who found it too hard to handle.
It appeared unharmed and was being cared for at a government animal center, according to The Standard newspaper.
Conservation officials were trying to decide where to relocate the reptile, including whether it would join its predecessor Pui Pui at a wetland park.
Pui Pui, a saltwater crocodile, made headlines after it was spotted in a Hong Kong river in 2003. It eluded hunters including Australian experts for months before it was eventually captured.
Pet shop owners say some residents in the space-starved Chinese city of seven million keep reptiles like snakes or lizard as pets, it is extremely rare for someone to have a pet crocodile.
“People think it is amusing to keep a crocodile at first,” reptile pet shop owner Dio Chan told The Standard.
“But as it grows, they need to buy a larger tank and more food and other equipment and eventually they give up ownership.”