A system for the verification of a magnetically printed material as to whether it is genuine or counterfeit is disclosed having magnetic and photo sensors arranged on the same scan line relative to the magnetically printed material for reading magnetic and optical patterns on the same scan line, and a first discriminator for, after the magnetic and optical patterns are superimposed one above the other at the same check point, discriminating change in level thereof. The system may further comprises a second discriminator for discriminating a change in level of the magnetic pattern. A combined optical and magnetic sensor assembly for the system is also disclosed.