A composite material that includes a layer of reinforcing fibres impregnated with a curable resin matrix and a plurality of electrically conductive composite particles positioned adjacent or in proximity to the reinforcing fibres. Each of the electrically conductive composite particles is composed of a conductive component and a polymeric component, wherein the polymeric component includes one or more polymers that are initially in a solid phase and are substantially insoluble in the curable resin, but is able to undergo at least partial phase transition to a fluid phase during a curing cycle of the composite material.