A dermatoglyph detector includes a detection circuit and an electronic processor unit. The detection circuit includes an electrically conductive thin film in which there are formed both electrodes that are arranged to come into contact with the skin of a portion of a human body and also conductive tracks connecting the electrodes to the processor unit. The processor unit is arranged to determine electrical characteristics of the body portion extending between each pair of electrodes in contact with the skin, and to execute a computer program for acting on the basis of the determined electrical characteristics to distinguish between an authentic body portion and a fake body portion. The detection circuit includes at least two track segments of different shapes between two calibration terminals so as to present an impedance ratio that is not equal to unity.