Pb2FeMO6 phases are of interest as potential multiferroics. We have prepared a new non-centrosymmetric pyrochlore-derived structure containing anion vacancy ordering (composition Pb2FeTeO6.5). Treatment of this under high pressure leads to the formation of a new double perovskite Pb2FeTeO6. Both materials show magnetic ordering transitions. Variable temperature neutron powder diffraction data is necessary for detailed study of the crystal structures (particularly oxide anion vacancies in the pyrochlore phase and displacements associated with perovskite tilts) and the low temperature spin ordered structures, plus any magnetostrictions arising from spin-lattice coupling.