An elongate hollow structure such as a pipe (10) and a method of constructing such an elongate hollow structure. The pipe (10) comprises a radially inner portion (11) and a radially outer portion (13), with the two portions (11, 13) merging together to provide an integrated tubular wall structure. The method comprising: providing the radially inner portion (11) in the form of an inner tube (21) and assembling the radially outer portion (13) about the inner tube (21). The outer portion (13) comprises an outer tube (30) of fibre reinforced composite construction surrounded by a flexible outer casing (31). The inner tube (21) is expanded to give form and shape to the outer portion (13).