A DVD disc is held in a seat (4) of a casing's back cover (2) by a central retainer (6). Four barriers (7), two on each of opposed sides, are integrally moulded in the cover (2) and face upwardly towards the seat (4). When the front cover (3) is closed the barriers (7) press against it, closing the gap between the covers. If a thief tries to slip a disc out of the casing, movement is blocked by the barriers (7). Another barrier (201) is connected to the retainer (205) and can only be removed by breaking it. This also provides a tamper-evident seal.
