Colloidal particles trapped at a fluid-fluid interface can be pushed down or pulled up by electric stresses due to the so-called "electrodipping force''. The resulting interfacial deformations lead to lateral capillary forces. For monolayers composed of polystyrene latex particles, the effect is however found to be weak. This is an important observation to understand the nature of the charge distribution around such particles at the water-oil interface. However, when a composite monolayer is prepared using particles with sufficient contrast in the dielectric properties, an electric field induced capillary trap can be created. In the present work, titanium dioxide particles are shown to behave as capillary traps for polystyrene particles when an external DC electric field is directed orthogonal to a planar water-oil interface.