Sarah Francis, who dives with the Scuba Republic dive centre in Roxton, Befordshire, discovered the weapon during a river clean-up in St Neots, so they called the police. Firearms officers were sent and took what was initially thought to be a live army pistol, for analysis. Dive instructor Dave Forster, who led the clean-up, said: She found it just below the bridge. Its the first time we have ever found a gun. We were expecting to pull out loads of shopping trolleys but there were just four, as well as a toilet cistern, five bikes and loads of tubes. But its the first time we have ever found a gun. It was in a really bad state so its been there for a while. The five star PADI dive centre is required to do something positive for the environment in order to keep its status. Dave says the River Great Ouse clean-up will now be an annual event for their divers.