The bomb squad were called to a property on Streton Road, Alfreton on Wednesday April, 30 after what was believed to be a bomb was discovered.
The property owner was undertaking groundwork at the time when they came across a metal cylinder which they believed to be a bomb.
The police were called and the bomb squad was immediately dispatched to the scene due to the serious nature of the incident.
After intensive investigation the cylinder was discovered to be an old bell that heavily resembled the nose end of a torpedo bomb and was in fact home to a several mice.
Once it was established that it was of no threat police left the scene.