British police have called off their search for a lion that was believed to be on the loose in Essex, in England's south-east.

The alarm was raised over the weekend by several holidaymakers staying in caravans in the seaside town of Clacton-on-Sea, who said they had seen and heard a lion wandering in a field nearby.

Tourists and residents were told to stay inside as armed officers spent the night scouring the area.

A police helicopter with heat-seeking equipment was deployed alongside zoo workers armed with tranquilliser guns.

A local zoo and travelling circus were quizzed, but neither reported any missing animals.

As the day progressed photos were produced that police now believe are fake.

The official conclusion is that it was not a hoax, but that everyone probably saw a large domestic cat.

"Extensive searches have been carried out, areas examined and witnesses spoken to, yet nothing has been found to suggest that a lion was in the area," a statement from police said.

Police explained that public safety had "remained at the forefront of the policing operation, with the force advising people to once again return to normal life".

ABC/AFP