THIS is the first picture of a 90-year-old gun raised from the seabed in Dover Harbour.

Mystery surrounds the discovery of the gun by the crew of the Port of Dover dredger, David Church, while they were carrying out maintenance work alongside the jetty at berth number two at the Eastern Docks.

Normally they lift nothing more exciting than pieces of chalk, old tyres and scrap from the sea bed.

"It made a nice change to find something interesting," said crew member David Casson who was driving the ship's crane when he grabbed the object.

Captain Ian Clark said: "When it emerged from the sea, he thought it was an engine prop shaft which had dropped off a lorry. But as he swung the job round onto the vessel, I realised it was a weapon. As I shouted to him not to drop it, he promptly did, but luckily it was not live."

The port authority contacted Royal Armouries' Fort Nelson Museum at Portsmouth and curator Phil Magrath identified it as a quick-firing three-pounder gun, manufactured by the Elswick Ordnance Company in Newcastle in 1916.

Mr Magrath said: "Guns of this type were fitted to all classes of naval vessel prior to the First World War, essentially as an anti-torpedo boat gun, but by the time of the war they were obsolete.

"Another possibility could have been its used on defensively armed merchant ships, yachts and trawlers, which may explain its presence in Dover.

"There does appear to be some damage to the gun but how this happened is impossible to say. It most certainly would have been fired shortly after its manufacture to be proofed, but whether it was fired in action is impossible to determine at this stage."

The gun is now in a desalination tank where it will remain for some months. Mr Magrath added: "Unfortunately there are patchy layers of concretion over the gun and these cover the area where I would expect to see the all-important gun register number.

"In time this concretion can be removed to hopefully reveal that number and maybe then surviving logs can tell us a little more about its history."