As well as the calculators, officers took 10 toy shotguns, telling surprised staff at the Present Finder in Sherborne that the toys could be used in criminal activities if they fell into the wrong hands.
The Present Finder?s Josh Hunt told Shooting Times of his shock at the seizure.
?It?s a bit of a joke to be honest. We had a visit from the police, and now we?re under investigation.?
Dorset Police later said that the calculators would be returned to the shop, but that the shotguns would be not be handed back, as ?they could cause distress to the public?.