A wildlife expert believes reports of a panther-like beast on the prowl in Sussex are probably sightings of a leopard.

Neil Arnold is convinced leopards, pumas and lynxes are on the loose and living wild across the county.

A milkman and a postman called the police after seeing what they thought was a black panther in Southdown Road, Portslade, in the early hours of last Thursday.

However, Mr Arnold, who runs Kent Big Cat Research, said: "The animal in question is probably a melanistic leopard, which simply means it is a normal, spotted leopard but with a dark coat.

"These cats live for about 16 years in the wild. The Brighton cat has not been released from a private collection but is from a second generation of cats that may have been set free during the Sixties and Seventies.

"They reach about 5ft long, have a lengthy tail and feed off rabbits, foxes, rodents and lambs."

One theory among investigators is that many big cats were released into the wild after the 1976 Dangerous Animals Act, which banned people from keeping exotic pets without licences.