Abstract: A non-reusable locking device for sealing containers. The locking device employs an insertion bolt which is insertable into a receptacle having locking flanges to prevent removal of the insertion bolt once inserted into the receptacle. A rigid housing surrounds and protects the receptacle, preventing access to the insertion bolt once inserted into the receptacle. A multi-part locking collar secures one end of a flexible cable permanently and rotatably within the housing. The second end of the cable is crimp-secured into a bore at one end of the insertion bolt. The flexible cable permits attachment to any type of container. The device forms a contiguous loop which can not be severed without destruction of the device. Once the loop is severed, it cannot be rejoined and provides instant indication that the container has been tampered with.