We briefly review the recent results obtained by Fermilab experiment E791 on the Dalitz plot analysis of the decayD+→ &Kgr;−&pgr;+&pgr;+, where indication for a light &Kgr;&pgr; scalar resonance, the &kgr;, was found. We also present preliminary studies providing further information on the phase behavior of the scalar components at low mass, supporting the previous indication for the &kgr;. © 2003 American Institute of Physics