Abstract: It is a system and method for the monitoring of the illicit traffic of fissile materials that can be used for the construction of nuclear bombs or not fissile that can be used for the construction of radiological dispersion devices; characterized by reducing the rate of spurious detection and increase the probability of detection compared with equivalent devices of the prior art. Some of its embodiments include the use of a radiation detector/telemeter ensemble with manual or automatic pointing and an ensemble of radiation detector/camera with an automatic object tracker along with data acquisition and processing electronics; which allow the calculation of the correlation between the characteristic profile produced by the MO and a predicted reference profile. The detection electronics includes a gamma spectrometer and processing electronics for compensating for the shadow shielding effects.