THE EXPLOSIVES Deactivation Unit (TEDAX) of Alicante Police were called to a nearby post office when a live two-inch mortar was found in a shipment.
A vintage war grenade was intercepted by staff on its way to Majorca, with explosive remains still inside.
The item had been bought online as a decorative item, and was en route when staff became suspicious.
Sources claim that other items had been bought from the same 42-year-old Alicante man, but none had previously been associated with explosives.
Police agents confirmed the mortar grenade was potentially explosive, and could cause serious damage during handling.
The seller was traced and is being held for crimes of possession of explosives and public disorder.