Dielectrophoresis of particles in liquid media has been well studied under the assumption of ideal dielectrics. Real dielectrics exhibit non-zero conductivity, however, and this fact brings about behaviours unpredictable by the model of ideal dielectrics. In the present work some attempts to experimentally investigate the dielectrophoretic motion of a lossy dielectric sphere suspended in a liquid under the action of a non-uniform electric field are described. The experimental results, compared with some theoretical predictions, offer more insight into the mechanism of the motion of lossy particles in insulating liquids of non-zero conductivity.