Optical sealing device for a container, and method of detecting tampering using this device

Device for sealing a container and method for detecting an attempted burglary using this device. In known manner, one part of the fibers is masked at one end of an optical fiber cable (22) and the other end of the cable (22) is observed when the first one is illuminated. According to the invention, the two ends of the cable (22) are held in a seal body (2) while the masking is obtained using an energy beam (56) which destroys the end of some fibers; observation of the second end of the cable (22) is done either with a camera or with a sighting camera (74) for locating the coordinates of the unlit fibers (A₁ , B₁, C₁). Application to detecting an attempt to open a container.