A method and device are revealed to non-invasively identify hidden foreign objects in proximity of living tissue. More specifically to a method and device find a foreign object hidden under the clothes of a person by measuring an anomaly in an infrared radiation signal emitted by the human subject; the anomaly caused by the presence of the foreign object. A spectral scan at the identified location is used to identify the object. Even when the object is hidden behind clothes, the object is positively identified based on the interaction of optical radiation naturally emitted by the human body in the infrared frequency spectrum with every component of the examined object.