The IMDT Act is an instrument passed by Indian Parliament when there was no MP elected from Assam, to detect illegal immigrants (from Bangladesh) and expel them from Assam. While the IMDT Act operates only in Assam, the Foreigners Act (1946) applies to the rest of the country. It is applicable to those Bangladeshi nationals who settled in Assam on or after 25 March 1971. Under the Act, the onus of proving the citizenship of a suspected illegal alien rests on the complainant, often the police. On the other hand, according to the provisions of the Foreigners Act, the onus lies with the person suspected to be an alien.