An AK-74 assault rifle was handed in to a London police station after being found in a bush by shocked council workers.
Gardeners cutting back bushes in Webber Row, Southwark, called police yesterday morning when they found the weapon.
The gun is widely used in the Russian Army and has a firing rate of 650 rounds per minute.
Met Police officers attended the scene around 11.40am and removed the rifle for forensic testing.
It has since been established that the gun had been decommissioned.
Southwark Police’s Acting Detective Superintendent Nicola Duffy said: “Firearms - whether decommissioned or not - have the potential to cause fear and harm and I am glad this weapon is now off the streets.
"I would urge anyone who has information that could assist police in removing firearms from the community to contact us.”
Southwark CID are investigating and no arrests have been made.
Anyone with information should call police on 101 or Crimestoppers anonymously on 0800 555 111
