For decades, India has received a constant inflow of unauthorized migrants from Bangladesh. According to a survey conducted by the Indian Statistical Institute in 2002-2003, most have economic reasons for migrating, such as poverty and the lack of employment opportunities, in addition to political instability.
These migrants generally find work as cheap labor in the informal sector, often as domestic helpers, construction laborers, rickshaw pullers, and rag pickers. The Bangladeshi government does not officially recognize those migrants and thus does not provide help or support.
In 2003, Bangladesh's foreign minister was quoted as saying that not a single unauthorized Bangladeshi resided in India.
As with most illegal migration, data on its extent is scarce. The Home Ministry estimated the number of unauthorized Bangladeshis as of December 2001 at 12 million, residing in 17 Indian states. However, in February 2009, the Home Ministry withdrew these data as "unreliable" and based on "mere hearsay."
Political scientist Kamal Sadiq has estimated the number of illegal migrants from Bangladesh at 15 to 20 million, basing the number partly on documented growth of Muslim communities and partly on unpublished government reports.
Sadiq's research has found that many of these Bangladeshis adopt Hindu names and are able to obtain fraudulent documents that allow them access to government subsidies and even to vote in elections. Indeed, some Indian politicians have benefited from votes cast by illegally resident Bangladeshi migrants.
As recently as April 2008, the
Indian Supreme Court directed the government to take all possible steps to prevent the "illegal immigration and infiltration" of Bangladeshis into India, while approving of the government's ongoing efforts, such as fencing off the India-Bangladesh border.