More than 30 staff were forced out of a Devon police station when a man brought in a hand grenade.
The grenade was placed in a secure container at the back of the station
The grenade was found in an allotment in St Michael's, Paignton, by a man who put it in his car and drove to the town's police station on Monday.
The rusting weapon, thought to be a World War II Mills grenade, was placed in a secure container at the station.
A bomb disposal unit which dealt with the grenade said the finder was lucky to be alive.
Police spokesman Joe Head said the grenade was severely corroded.
"Part of the handle was corroded so it could have gone off at any time," he said.
The anti-personnel grenade was put in a bomb suppression container outside the rear of the station which was evacuated.
It was then covered in sandbags before it was taken away for disposal at Goodrington Sands.
Mr Head said: "Our advice to anyone who finds a device like this in the future is to leave it where it is, do not touch it and call the police."