Spalding Police Station was closed for enquiries briefly today after a World War mortar shell turned up on its counter.
The military weapon was brought in by a resident in the middle of a week-long firearms surrender organised by Lincolnshire Police.
People can take their unlicensed or unwanted firearms, ammunition, war memorabilia and imitation weapons to any police station between now and Monday, without facing charges.
Speaking about the wartime delivery to Spalding Police Station, a spokesman said: “A member of the public had brought in a World War II mortar shell that had been in their attic for years.
“We closed public access (to Spalding Police Station) until an explosive ordnance disposal team arrived.
“They have taken the mortar shell away and it is likely that they will be carrying out a controlled detonation.”