Whereas in a case where the initial assessment order is under Section 143 (3), and it is sought to be reopened within four years from the expiry of the relevant assessment year, the AO has to base his ‘reasons to believe’ that income has escaped assessment on some fresh tangible material that provides the nexus or link to the formation of such belief. In a case where the initial return is processed under Section 143 (1) of the Act and intimation is sent to the Assessee, the reopening of such assessment no doubt requires the AO to form reasons to believe that income has escaped assessment, but such reasons do not require any fresh tangible material