A metal detection apparatus includes a transmitter for generating a magnetic field in the vicinity of the metal object, and a detector for detecting a secondary magnetic field. The detector include a first gradiometer for providing a first output signal representative of a first direction, y, to the metal object, a second gradiometer arranged substantially orthogonal to the first gradiometer for providing a second output signal representative of a second direction, x, to the metal object, the second direction being substantially orthogonal to the first direction and in the same plane as the first direction, and an outer coil and an inner coil arranged to be substantially concentric with one another and each of which is arranged to provide an output signal representative of secondary magnetic field strength in a third direction, z, which is substantially orthogonal to the plane of the first and second directions.