The police station in Spalding and several nearby homes were evacuated for over an hour on Sunday over explosion fears.
This was after what appeared to be a hand grenade was taken to the police station by a person at around 11.20am on July 14.
Lincolnshire Police called in the Explosive Ordinance Department to examine the item, which turned out to be a dummy grenade.
Cordons of 100 meters around the police station were lifted at around 12.40am.
“Apologies for any inconvenience but better to be safe than sorry!” police said.