Device for locking an automobile steering column

The device (7) has a casing (15) housing a locking mechanism that comprises a bolt (21) displaced from an unlocking position to a locking position in which the bolt is engaged with a locking recess (23) of a steering column (3) of a motor vehicle. A blocking mechanism (17) is displaced from an unblocking position to a blocking position to block the locking mechanism in the locking position. The blocking mechanism is triggered during a casing opening/deterioration action. A theft attempt detection unit (19) cooperates with the blocking mechanism for triggering a vehicle securing unit. An independent claim is also included for a motor vehicle safety device comprising a vehicle securing unit.