Abstract: The invention relates to a theft deterrent device which can be lockably fastened to an article (4) made of cloth, leather, skin or like material, in a manner such that it can only be removed from the article with the aid of special means intended therefor. The device is, to advantage, in the form of a clamp which can be closed around an edge part of the article and therewith automatically locked in position. Arranged in the two halves of the clamp-like device are steel pins which penetrate the material from which the article is made, so that the device sits firmly thereon. The device includes one or more enclosed spaces, preferably in the form of glass ampoules (19) arranged in cavities (15) in the device. The ampoules contain a heavily staining and/or ill-smelling substance, for example a gas or liquid under pressure, and are arranged to break readily if an attempt is made to remove the device by force.