An invasive species of turtle has been found in the Hunter for what the Department of Primary Industries believes to be the first time.
A red-eared slider turtle was found on a path by a couple walking to Caves Beach before Christmas.
The species originates from parts of the USA and Mexico, but there are non-native populations found worldwide due to it being extensively traded as both a pet and a food item.
There is known to be a population living in the Georges River in Sydney, and the Department of Primary Industries has had one report of the turtle being found on the Central Coast, but the Caves Beach find is the first in the Hunter region.
The turtle was found near a stormwater retention pond and initially taken into care by Hunter Wildlife Rescue.
"It was suggested that someone had seen the animal near that dam maybe this time last year," the department's invasive species officer Ian Turnbull said.
"So whether it's the same animal or not, that's probably our million-dollar question: is it one or is there an established population there?"
The International Union for Conservation of Nature considers the red-eared slider "one of the world's worst invasive alien species".
Outside of its natural range, it is considered an environmental pest because the species competes with native turtles for food, nesting areas and basking sites.
"It's most likely been dumped or escaped from an illegal collection and has been living there," Mr Turnbull said. "It's about 20-centimetres long, but they can get quite large.
"Initially when people have them they are a tiny little thing like a 50-cent piece, but they grow into this three-kilo monster that's aggressive and they're not too much fun to have as pets anymore."
Mr Turnbull said the species was listed as a non-native animal under the Biosecurity Act 2015 and anyone caught with one could face a hefty fine.
"They're definitely still being actively illegally traded," he said.
"They're prolific breeders, they will out-compete the natives for food, basking sites and nesting sites, and pretty much if the foxes don't get them they will take over an area.
"Like most reptiles, they're a carrier of salmonella and that's a concern. But primarily it's the disease risk, also, of these imports coming in."
The department will use specially trained detection dogs to check water samples from the pond and potentially set up camera traps to see if there are any other red-eared slider turtles in the area.