Two dead piranhas have been found in a pond in Middleton, Greater Manchester, environmental officers have revealed.
Experts say the piranha's fearsome reputation is exaggerated
The flesh-eating fish were netted by a local fisherman at the Rhodes Lodge pond in Middleton.
Environment Agency officers believe the piranhas were put in the water as live bait to lure other fish.
"Putting tropical fish in lakes and ponds is not only illegal but extremely cruel," said the agency's tropical fish specialist Bernie Chappel.
"The water would have been far too cold and the fish would have suffered a slow death."
Introducing non-native species of fish into UK waters without authorisation from the Environment Agency is illegal because it can damage the country's natural fish stocks.
The ban even extends to goldfish.
If those responsible for the piranha's presence in the pond are caught, they face a fine of up to £2,500.
The Agency has appealed for anyone who knows who owned the fish to contact them.
Although piranhas are supposedly capable of stripping the carcass of an animal within minutes, experts believe their fearsome reputation is exaggerated.
The species cannot survive in temperatures below 15C