The bomb squad were called to Hereford Police Station earlier after a device was handed in.
Police have confirmed a single grenade was handed in at the station.
A cordon was erected around the station while the military explosive ordnance disposal team accessed the device.
The grenade was found to be empty and the cordon has since been lifted.
Officers say a man had dug up the grenade in his back garden before bringing it in to the station.
Creative hub planned for former estate agent’s office
Person found dead on railway track
Strike at Abergavenny King Henry School parents react
Teachers strike continues at Abergavenny school
Eight-figure sum quoted to fix Ledbury station access