This work is focused on the image reconstruction of defects in metallic materials using time-harmonic eddy currents testing measurements. The proposed approach combines an efficient numerical model of the probe-defect interaction and a least square error regularized procedure for solving the inverse problem. The method has been successfully tested to detect multiple volumetric defects on multiple layers of a planar conductive material. The regularization term is the total variation, selected to “encode” the a priori information that defects are supposed to be “blocky”. In this manner, the method is potentially capable of treating on the same foot several defects type such as EDM, fatigue crack, stress corrosion crack etc.