From the telegraph
Water company engineers spotted the object when they lifted up a fire hydrant cover during work on a street in Shoreditch, east London.
The road was cordoned off and a nearby pub was evacuated amid fears that the "grenade" could explode.
The fictional weapon looks more like a golden ornament than a hand grenade; it was based on the Sovereign's Orb used at royal coronations.
The prop has become a popular in-joke among Python fans and replicas can be bought on eBay for as little as £14.
An spokeswoman for Islington police confirmed that the device was a toy and that had been no danger to the public
Local businesses criticised the police for taking so long to realise there was no threat.
Alberto Romanelli, owner of the Windmill put that was evacuated, said: "I lost a good hour's worth of business."