A unbonded flexible pipe with a length and a longitudinal axis is described. The pipe comprises an innermost sealing sheath defining a bore, at least one armor layer surrounding the inner sealing sheath and at least one optical fiber containing layer, wherein the optical fiber containing layer comprises at least one tape and at least one optical fiber arranged with a length of at least about 3 times the length of the flexible pipe. In an embodiment the optical fiber is incorporated into the at least one tape of said optical fiber containing layer to provide an integrated fiber tape where advantageously the optical fiber is arranged with S-shaped folds.