For years it gathered dust – maybe in an attic or a shed somewhere, possibly in a box on top of somebody's wardrobe.

Somehow, a First World War pistol was scooped up in a pile of clothes and handed into a charity shop.

Now, the gun – a prized possession of Captain Hugh Winfield Sayres, who died on the first day of the Battle of the Somme – is finding a new home in a museum.

The discovery of the pistol – a Wilkinson Webley revolver – was made when staff at the Earl Shilton shop rummaged through a bag of old clothes.

Normally, the working gun would have been deactivated and dismantled, but after hearing of the discovery, amateur history enthusiast Sergeant Rich Matlock, of Loughborough police station, stepped in to save it.

His investigation unearthed the story of a dedicated officer, with a distinguished military career, who fought and fell alongside the men he led.

Sgt Matlock discovered that Captain Sayres was born in 1888 and came from London. He joined the Army as a "gentleman cadet" in 1909. After passing out at Sandhurst, Sayres joined the Lancashire Fusiliers.

The gun was bought privately in 1912 at Wilkinson Firearms, in London's Pall Mall, and inscribed with his name.

Capt Sayres was posted to India in 1912 and in 1915 was shot in the right shoulder while landing in Gallipoli.

After recovering, he was posted to France and promoted to acting major, but asked to return to his battalion as a captain so he could fight with his soldiers.

Aged 27, he was killed on the first day of the Battle of the Somme – July 1, 1916 – with his dog, Nailer.

Later this month it will be presented – along with all Sgt Matlock's research and photographs – to the Lancashire Fusilier Museum, in Bury.