The act were at services off the M1 when the incident happened on Sunday night, according to Leicestershire Police.

The five were recognised by a group of youths at Leicester Forest East services at about 2130 BST.

One of the youths waved what appeared to be a handgun but no threats were made.

Myleene Klass, Suzanne Shaw, Noel Sullivan, Danny Foster and Johnny Shentall left the services in their vehicle after alerting the police.

But they called the police again after they were caught in a traffic jam and spotted the car the men were in on the motorway.

Man arrested

Insp Mark Martin said: "It appears it was later discovered the weapon was an imitation."

Police could not confirm reports a ball-bearing shot was fired from the gun.

Officers from Northamptonshire Police were called after the cars crossed the county border.

Insp Bob Michelmore, of Northants Police, said Hear'Say and their tour manager Graham Quinn reported the incident from the services and the motorway.

Northants Police arrested a man in connection with the incident.

He was interviewed by Leicestershire Police and released on bail to return to a police station next month.