We have studied the charge transport and dielectric properties of KH2PO4 (KDP) single crystals, irradiated by proton beams with high energies up to 20 MeV, by means of the temperature-dependent electrical conductivity and dielectric constant measurements. It is shown that the electrical conductivity and the electric dipole moment may be sensitively controlled by the proton irradiation energy and dose. The activation energy and the dipole moment were shown to be strongly correlated. (C) 2014 Elsevier B.V. All rights reserved.