An elongate element (300) for a flexible pipe body (100) and method of producing the same are disclosed. The method includes inserting a first fiber element (304) in a crush resistant elongate tube element (302), wherein the first fiber element is suitable for monitoring at least one of strain, temperature and acoustic properties; inserting a further fiber element (306) in the tube element, wherein the further fiber element is suitable for curing a matrix material (308); and inserting a matrix material into the tube element to fill at least a length of the tube element such that the first and further fibers elements within that length are surrounded by matrix material.