A locking device comprising a lock body having a through hole, a bolt member having a longitudinal bore therethrough and an insertion end which is inserted into the through hole of the lock body. The bolt member is further having a retaining pin disposed within the longitudinal bore and a resilient means for biasing the retaining pin axially out of the longitudinal bore. When the bolt member is inserted into the lock body, a means within the lock body prevents the removal of the inserted bolt member therefrom, and engages an actuating means to actuate an identifying means. The identifying means transmits a signal to indicate whether the locking device has been tampered with or defeated. If the bolt member is cut, the retaining pin is displaced out of the longitudinal bore and dislodges the actuating means resulting in the identifying means indicating that the locking device has been tampered with or defeated.