The Spanish customs service found 1,085 guns and pistols on a ship making its way from Israel to Nicaragua during a routine inspection of the ship while it was docking in Algeciras in southern Spain.
The container was confiscated by the Spanish authorities, and the ship was later permitted to set sail.
The ship's bill of customs noted that the ship was carrying air rifles.
The weapons container was found on the vessel Maersk Detroit, which set out from Haifa and was headed for the Managua Port in Nicaragua, via the US.
Local security personnel confirmed the report, but failed to indicate the number of weapons found.
Following the September 11 terror attack, the US issued an instruction requiring all cargo ships headed for the US to stop at the Spanish port and undergo an inspection before continuing on their journey.