Heavy ions in the Jovian plasma disc can be heated as they diffuse outward under the influence of the centrifugal force if they are scattered with an effective collision frequency which is comparable to their gyrofrequency. The purpose of this paper is to see if the random electric fields having temporal and spatial scales of the ion gyration can act as sufficiently efficient scattering agents. The diffusion process is studied by numerically tracing the trajectories of sets of heavy ions subjected to the centrifugal force and the random electric field. The random field of inferred intensity is found to produce significant diffusion of heavy ions. These ions are heated to the level of the kinetic energy of the local corotational motion. We suggest that the above mechanism contributes in supplying the high-temperature heavy ions to the outer Jovian plasma disc.