Four men suspected of stealing a horse box were arrested yesterday, when they were pulled over by a routine number plate check.

An automatic number plate recognition (ANPR) camera alerted the police that a large 4x4 with a trailer had “no keeper” details, meaning that the vehicle wasn't registered to anyone.

The empty horse box was missing its number plate, which caused an officer on the scene to investigate further.

The previous owner was called, and on discovering she hadn't recently sold the horse box, was asked to confirm it was missing from her property.

All four men were arrested and both vehicles were recovered and checked over by scene of crime officers.

The ANPR camera is primarily used to detect vehicles with no insurance or tax, but also points towards other crimes which may have been committed.

Sergeant Dave Simkin said: “The ANPR also alerts us to different crimes, sometimes people may be drink or drug driving.

"We also know that burglars who steal large high value items need a car to take them away.”

The operation was set up in Bushey and later on the A41 yesterday afternoon, and had already resulted in one car being taken off the road due to it not being insured.

Sgt Simkin added: “People who fail to maintain their payments find that their insurance company can cancel their policy.

“If the car is seized we give the owner 14 days to get the car insured, but they'll still be fined £200 plus storage costs and receive six points on their licence.”