Theft-deterrent device for use with theft-attractive articles

In a theft deterrent device for use with theft-attractive articles or goods, comprising a first element (10) having an elongated connecting member (12) which projects from the first element (10) and which in use is inserted through an article to be protected, and a second element (14) which in use is attached to said connecting element (12) and locked thereon against movement away from said first element (10) so as to hold the deterrent device firmly on said article, the improvement wherein

• the first element (10) consists essentially of said elongated connecting element (12) and a button-like head at one end thereof;
• and
• said second element (14) includes an elongated casing (16) housing a fragile marking-substance containing ampule (44) and a release part (30) projecting outwardly in a direction away from the first element (10), said release part (30) defining an internal cavity extending in length in a direction aligned with said elongated connecting element (12);
• a locking unit (18) disposed at least in part inside the internal cavity defined by said release part (30), said locking unit (18) in use receiving and locking said elongated connecting element (12);
• said ampule (44) and said locking unit (18) being so disposed relative to one another that when the connecting element (12) is improperly attempted to be pulled from said second element (14), said locking unit (18) is brought into contact with said ampule (44) such as to cause said ampule to fracture and thus release the marking-substance contained therein.