Locking cap for a container that has a neck, said cap being intended to block a stopper in the neck of the container and comprising: - an outer body , - a cage which is designed to fit into and lock axially in the outer body and is intended to surround a collar of the neck of the container in a locked position of the cap ; the cage comprising: - an upper ring against which the stopper is intended to rest when it is arranged in the cage , - a plurality n of arms which are connected to the upper ring and define therewith a generally cylindrical shape of the cage , - n/2 first bridges and n/2 second bridges , each interconnecting two adjacent arms , the first bridges and the second bridges being arranged alternately over the periphery of the cage , characterized in that the cage has a breakable area , and the outer body has a breakable part ; the breakable part of the outer body and the breakable area of the cage being designed such that, when the cap is in the locking position on the container , the breaking of said part and said area allows said cap to be removed from said container , the cage comprising - at least one opening tab , which is supported by a second bridge which is inclined toward the outside of the cage and is oriented toward the upper ring , said opening tab being adjacent to the breakable area , which is located on said second bridge , and the application of a tensile force to the opening tab being capable of causing breakage in the breakable area . - an outer body , - a cage which is designed to fit into and lock axially in the outer body and is intended to surround a collar of the neck of the container in a locked position of the cap ; the cage comprising: - an upper ring against which the stopper is intended to rest when it is arranged in the cage , - a plurality n of arms which are connected to the upper ring and define therewith a generally cylindrical shape of the cage , - n/2 first bridges and n/2 second bridges , each interconnecting two adjacent arms , the first bridges and the second bridges being arranged alternately over the periphery of the cage , characterized in that the cage has a breakable area , and the outer body has a breakable part ; the breakable part of the outer body and the breakable area of the cage being designed such that, when the cap is in the locking position on the container , the breaking of said part and said area allows said cap to be removed from said container , the cage comprising - at least one opening tab , which is supported by a second bridge which is inclined toward the outside of the cage and is oriented toward the upper ring , said opening tab being adjacent to the breakable area , which is located on said second bridge , and the application of a tensile force to the opening tab being capable of causing breakage in the breakable area . - at least one opening tab , which is supported by a second bridge which is inclined toward the outside of the cage and is oriented toward the upper ring , said opening tab being adjacent to the breakable area , which is located on said second bridge , and the application of a tensile force to the opening tab being capable of causing breakage in the breakable area . <EOS>