<h1>Reverse migration of undocumented Bangladeshi nationals follows electoral roll verification requiring biometric checks and risking detention.</h1> The Special Intensive Revision (SIR) of electoral rolls has prompted undocumented Bangladeshi nationals to seek return from West Bengal to avoid mandatory verification; biometric details are transmitted to district authorities and police, producing large daily detention-and-pushback figures, verification delays, strain on local policing, and humanitarian needs as persons who obtained identity documents through intermediaries leave rather than risk questioning.