The medallion was dated two days before the boat sank

The artefact is rare because it is dated two days before the Lusitania was sunk.

Medal maker Karl Goetz of Munich dated the medallion 5 May 1915 when it should have read 7 May 1915.

Now West Yorkshire Police are trying to find the medal's rightful owner.

The British liner set sail from New York to Liverpool carrying nearly 2,000 passengers and crew.

More than 1,200 people lost their lives

The Germans had warned the British the liner was entering a war zone, but Captain William Turner thought it could outrun any U-boat in the area.

She was struck off the coast of Ireland - with the loss of 1,200 lives, an action that hastened America's entry into the war.

Police found the medal in the glove box of a car which they stopped in Thornton Road, Bradford on 12 March.

The driver ran off leaving the car and its little piece of history.