A range of water-in-oil micelle systems of low water concentration, <5% by weight, have been examined by dielectric spectroscopy in the frequency range from 10(5) Hz to 10(-5) Hz. In the higher frequency range above about 1 Hz the systems can be described in terms of a parallel bulk conductance and capacitance. The effect of the water concentration on the permittivity and conductivity is small, indicating that all the water is bound into the micelles and cannot polarize. In the lower frequency range large dispersions in capacitance were observed and have been characterized in terms of the generalized Maxwell-Wagner effect due to the surfactant forming electrically blocking layers at the electrodes. With polyisobutenyl succinic acid as the surfactant anomalous surface structures of loosely packed micelles are formed and have been found to be unstable.