A load carrier including a fixing system on a rear part of a vehicle including: a longitudinal arm with one end to interact with a sleeve joined to a structural element of the vehicle; a lever with one end mounted to rotate relative to the arm about a transversal pin supported by the end of the arm; a device placed between the lever and the arm and exerting a force in a direction; and a lock for the fixing system. The lock includes a handle having a gripping part and a cam part mounted to rotate relative to the lever about a transversal pin supported by the free end of the lever between: (1) an unlocked state in which movement of the handle about the pin is free between a position in which it abuts against the free end of the lever and a position in which a point of a leading surface of the cam is in contact with the arm; and (2) a locking state in which movement of the handle about the pin and interaction of the handle with the arm causes the lever to rotate about the pin in a clockwise direction until reaching a locked end position of the lever at which the lever is stressed and joined to the sleeve.