A passenger travelling through Stansted Airport in Essex has been stopped by police after being spotted carrying an iPhone case designed to look like a gun.

Essex Police tweeted photos of the case, which when protruding from a back pocket looks like a black handgun, on 6 July. The force told its 700 followers it had a "split-second decision to make" when officers spotted the case.

The above image, mocked up by Essex Police, shows what looks exactly like a gun protruding from a man's back pocket. The force later tweeted to say the case was in fact found during a "routine security search" as the passenger passed through the airport.

Follow up images revealed how the "gun" is actually an iPhone case, but this is only apparently once it is removed from the owner's pocket. Essex Police said: "Someone decided to put themselves in such a situation today... Bringing this to an airport makes it much less likely you'll catch your plane. #dontbedaft".

Answering questions from a fellow police officer, the Twitter account said the offences committed here would likely be Section Five Public Order and "possibly" Section 19 Possession of Imitation Firearm in a Public Place. Peter Kirkham, a former police officer, added that carrying the case in an airport would be a "seriously aggravating factor" as if carried as demonstrated by Essex Police would "enhance appearance". As it stands, no charges have been brought against the passenger.

At the time of the incident the iPhone case could be bought on Amazon for £15.47 ($20) with free delivery. However, at the time of publication it is no longer for sale. But the Amazon page, featuring a photos showing how it can be worn in a back pocket to look more like a gun, is still online.

There are many iPhone gun cases available on eBay, with prices starting from under £3. "Be the envy of your friends" boasts one listing on the auction website, describing the case as "eye-catching". An accompanying iOS app can be downloaded to make firing noises when the trigger is pulled.