The hysteresis loop of ferroelectric thin film capacitors, shows sometimes non-saturation effects, i.e. the high electric field parts of the hysteresis loop do not close and the apparent remanent polarization increases with the amplitude of the measurement signal. Several models attributed this effect to the presence of leakage current, but the very high current levels predicted have not been always confirmed by the direct measurements of the DC leakage. Here, we show that the relaxation current, rather than the true DC leakage current can, in these cases, explains the non-saturating behavior. This effect would than not be caused by the movement of free charges, but rather to of the localized ones.