During a training flight for the purposes of demonstrating upset recovery techniques, the Pilot was demonstrating recovery from near inverted flight. On rolling the aircraft to recover to an upright attitude, the Pilot could not neutralise the ailerons. The ailerons were stuck with respective deflections of 10-15 degrees (starboard up, port down), with the aircraft rolled to the right. The Pilot managed his aircraft’s energy and attitude and safely landed the aircraft with the ailerons still restricted. On shutdown, the restriction cleared. Subsequent examination identified a loose bolt within the wing structure which was the likely cause of the restriction.