In this talk we will present results from the MAGNA (Multiple AGN Activity) project focused on the detection and study of multiple supermassive black hole systems. We investigate the physical properties (accretion rate and local environment) of multiple AGN candidates in interacting systems with respect to isolated sources with the goal to understand the mechanisms that trigger AGN activity in different stages of galaxy mergers. We report on an optical and X-ray study of an optically selected sample of four dual AGN systems at projected separations of 30–60 kpc. We compare the absorption properties in our dual AGN with those in larger samples observed in X-rays but selected in different ways (optical, IR and hard X-rays). We find that the obscured (NH~10²² cm^-2) AGN fraction within the larger sample is 84±4 per cent (accounting for the 90 per cent error on the NH measure) up to large pair separations (100 kpc). i.e. statistically higher with respect to the fraction of obscured AGN in isolated galaxies found in X-ray surveys. This evidence is in agreement with the hypothesis that galaxy encounters are effective in driving gas inflow toward the nuclear region, thus increasing the obscuration. The talk will reflect on broader implications of these findings and will present future perspective.