The paper reports on a composite based on a polydimethylsiloxane matrix filled with liquid metal and magnetic hard microparticles. The effect of the concentration of such a complex filler on the elasticity and relative permittivity of the composite has been investigated. Inclusions of liquid metal provide improved permittivity compared to the unfilled matrix, while the stiffening effect is not as high as when the matrix is filled with solid particles alone. On the other hand, magnetic hard fillers allow the functionalisation of the composite in terms of its magnetic properties. It is also shown that changing the residual magnetisation of the composite has no significant effect on the elasticity and relative permittivity.