Alligators and crocodiles are a common sight in Florida, but a new man-eating species has been found in the area.

The new species can grow up to more than 5 meters in lenght and weigh as much as a small car.

Using DNA analysis, researchers have confirmed the species to be a Nile crocodile. The crocodile eats anything from hippos to humans in its native Africa. Recently the reptile has been found swimming in the wetlands of South Florida and relaxing on house porches in Miami.

The study suggests that the invasive species can thrive in its new habitat. One juvenile crocodile grew almost 30 per cent faster than in some parts of its native range.

"We know that they can survive in the Florida wilderness for numerous years and we know that they grow quickly here," Kenneth Krysko, co-author of the study, said.

Nile crocodiles were responsible for at least 480 attacks on people and 123 fatalities in Africa between 2010 and 2014.

"We know their behavior in their native range, and there is no reason to suggest that would change here in Florida," Krysko continued.

The researchers have yet to confirm where the species came from. The most likely pathway to Florida is import of Nile crocodiles to supply Florida's blooming pet trade over the last decades.