Abstract: The present invention concerns a method, a system, the use of the system and a reinforcement member for the direct detection of the presence of a cavity in a drill-hole intended for the reception of a reinforcement member. The method comprises the injection of a drill-hole with hardening grout 6, the introduction of a reinforcement member 7, 40 to introduce a pressurised medium 37 and the measurement of the change in pressure or the detection of a flow of medium, whereby the fall in pressure or the presence of a flow of medium indicates the presence of a cavity.