The invention relates to a composite fibre intended, for example, for the basic production of fishing lines, characterised in that it comprises a twisted multifilament core (2) jacketed with a sheath (4) constituted by the winding of at least one fine wire with touching turns, such as, especially, stainless steel wire. The material constituting the core possesses a specific strength at least equal to 0.7 GPa, and this material may advantageously be "Kevlar", glass, carbon or boron. The field of the invention is that of the manufacture of flexible composite fibres, resistant to tensile forces and to abrasion, which are intended, for example, for the leader of lines for fishing for carnivorous fish. These fibres may also be of use in any field where there exists the need for a flexible and strong fibre. <IMAGE>
