A marking tape comprising at least one resonant circuit, each resonant circuit comprising an inductive coil and a capacitor, forming a resonant circuit of a selected frequency, comprises inductive coils and capacitors formed by conductive material layers (2, 3, 4) on the surfaces of a dielectric plastic film (1) and is dimensioned to be wireless detected when positioned in a hidden location. Such marking tape can be produced with low cost and provide a wireless detection of the integrity of a marking tape in a hidden position, e.g. from the surface above a subterranean positioned marking tape.