A police helicopter was scrambled and passengers were stopped from leaving a train after police received a report of a lion on the loose.
West Yorkshire Police received a call at 3.30pm on Sunday from a woman who thought she saw a lion as she was driving in the village of Shepley near Huddersfield.
The search lasted almost two hours as officers tried to locate the lion and passengers were forced to remain onboard trains at Shepley station.
But at 5.15pm the inquiry was ended as no lions were found and there were no additional sightings.
Inspector Carlton Young, of West Yorkshire Police, said: "We've had unconfirmed reports of a lion or a lion cub in the area. We've had officers looking around. At the moment we've had nothing confirmed and we've not located anyone who is claiming to have lost an animal."
Officers believe the woman - who claimed to have seen a lion on Penistone Road, Shepley - was a genuine caller. Around 12 officers were dispatched to look for a lion along with a police helicopter.
Insp Young added that the search would be resumed on Monday if there were any more reports.
National Rail Enquiries wrote on its Twitter feed: "Passengers are currently unable to alight from trains at Shepley due to reports by police of a lion in the area." It later issued an update that normal service had been resumed.
In May a police helicopter was scrambled and a golf course cleared after a white tiger was spotted in a field in Hampshire by members of the public - only to turn out to be a stuffed toy. Police received several calls reporting sightings of the tiger in a field near Hedge End, Southampton.
Specialist staff from nearby Marwell Zoo were called in to advise and potentially tranquillise the wild animal and a local golf course was evacuated. But as police officers carefully approached the dangerous animal they realised it was not moving and the helicopter crew, using thermal imaging equipment, realised there was no heat source coming from it.