A pair of amateur photographers were stopped and questioned after taking a photo of a police car near Croxley Green apparently because of fears over terrorism.

Kyle Adams and George Anastasi, both 26, had been taking photographs of the Grand Union Canal from the A412 when they heard a siren approaching.

The two say they were hoping for a dramatic shot as the car drove with flashing blue lights over the bridge crossing the Grand Union Canal near the Harvester pub.

To their surprise as soon as they trained their lenses, the Hertfordshire Constabulary car immediately switched off its lights, turned around and parked in front of them.

The officers then got out and began to question the two men about why they were taking photographs before checking their drivers licences over the radio.

Mr Anastasi said: “The police officers admitted they had no suspicions about us but “in this day and age, we have to ask anyone with a camera like yours what you’re up to, because of terrorism”.

“We were made to feel like we were doing something wrong.

“I got the impression if we had been taking photos of random things this wouldn’t be a problem, it is because we had trained our cameras on the car itself that we were stopped.”

The school friends, from Harrow, say they bought DSLR cameras 18 months ago and recently completed a beginner’s course in photography at Harrow College.

On July 4 they were keen to test out the equipment and their skills in the dusk.

Mr Adams said: “The conversation was relaxed to a point but whenever you talk to the police and are stopped you feel intimidated.

“We asked them why they were stopping us, they just kept saying you can’t trust people in this day and age.

“If I had taken a photo on an iPhone it’s likely nothing would have happened but with a DSLR you may as well be walking around with a gun.”

During the incident the men volunteered to show the officers their pictures, they were not asked to delete any images and none of their equipment was confiscated.

A Hertfordshire Constabulary spokesman said: “It is in the public interest for our police officers to be curious about behaviour that is out of the normal routine or where an issue like road safety might be at stake.

“The force recognises that the public duty also has to be balanced against the public interest for law-abiding members of the public to be able to go about their normal business unhindered.

“Through the course of their duty, police officers have to make many decisions about whether it is necessary to stop or challenge someone, knowing that in some cases they will have stopped someone who it transpires is just going about their daily routine.

“We hope in those instances that the public understands our wider responsibility around protection and exercises patience while appropriate checks are completed and they can then go on their way.”