Abstract: A method of improving the rate of detection of attempts at fraud when a person passes through a controlled space based on the use of different sets of parameters issuing from at least two different sensor systems, some sets of parameters being based on correlations of measurements issuing from various sensor systems. Learning is carried out so as to characterise various types of fraud to permit identification of attempts at fraud by correlation between measurements obtained and characterisations of each type of fraud for each set of parameters.