Shaun LowthorpePolice have launched an eight week amnesty on blank-firing revolvers.Shaun Lowthorpe

Police have launched an eight week amnesty on blank-firing revolvers used to start races and train dogs.

The campaign which runs until June 4 is a targeted amnesty, focused only on the Olympic BBM blank-firing revolver.

Officers are encouraging members of the public who use the guns legitimately to hand them in and not face prosecution, because the revolvers can be readily converted to fire live ammunition.

The gun now falls under the classification of a prohibited weapon, and people caught with them can face a five-year jail sentence.