A wireless power transmission system is designed to transmit power through a permeable conductive barrier layer. The system comprises a power transmitting circuit including a first inductive coil. A power receiving circuit includes a second inductive coil located on the opposite side of the barrier layer to the first inductive coil. A biasing magnet or electromagnet is provided and characterised by its ability to substantially saturate the magnetisation of the barrier layer in a region adjacent to the first and second inductive coils.