A 2024 interim report by Tata Institute of Social Sciences (TISS) on illegal Bangladeshi and Rohingya immigrants in Mumbai paints an alarming picture of a city being reshaped demographically, economically, socially and politically – without mandate, accountability or a clear state response. Far from being a marginal issue, the report argues that unchecked illegal migration is altering the very character, security profile and governance structure of India’s financial capital
Demographic Engineering In Slow Motion
Mumbai has long grown on the back of migration, but the report underlines a structural shift: even as the city reaches saturation, undocumented inflows continue to pour into already choked slums and bottleneck zones. This is highlighted not as organic urbanisation but as a sustained, under‑policed movement with clear demographic consequences.
The Hindu share of Mumbai’s population is reported to have fallen from 88% in 1961 to 66% in 2011, while the Muslim population has risen from 8% to 21% over the same period.
Projections cited in the study suggest that by 2051 Hindus could drop below 54% in Mumbai, while Muslims may touch around 30%, fundamentally altering the city’s religious balance.
The report flags roughly 90‑plus “pockets” and bottleneck areas where illegal Bangladeshi and Rohingya migrants have concentrated in significant numbers, often in religiously homogeneous clusters.
Localities repeatedly named include Govandi, Mankhurd, Dharavi, Kurla, Malvani, Nalasopara, parts of Turbhe, Ambedkar Nagar, and slum belts around industrial and transport hubs, where the demographic character is said to be shifting rapidly. These clusters are seen not as isolated communities but as expanding bases, continuously replenished by fresh illegal entrants through kinship, village networks and organised routes.
Routes, Networks And The Machinery Of Illegal Entry
The report maps illegal immigration as a deliberate, organised process, not an accidental spillover.
The India–Bangladesh border is described as porous, with crossings facilitated by human smugglers, touts, corrupt border officials and long‑standing informal trade routes.
Many migrants first enter eastern states such as West Bengal and Assam, obtain shelter and basic documentation through local facilitators, and then move on to growth centres like Mumbai and other western cities.
Interviews describe step‑by‑step journeys involving multiple hand‑offs: from village agents in Bangladesh to border operatives, then to transporters and job contractors inside India.
The report notes that some migrants circulate between Indian cities and home districts, while others remain long term, eventually “integrating” into slums as de facto residents despite having no legal right to be in the country.
This continuous pipeline, the authors warn, ensures that even sporadic crackdowns cannot meaningfully reverse the demographic or security impact unless the networks themselves are dismantled.
Labour Market Capture And The Shadow Economy
One of the most striking points made in the study is how illegal migrants have moved from the margins to the centre of Mumbai’s low‑skill labour market.
After Covid‑19, when many local Maharashtrian and other Indian workers returned to their native states, illegal immigrants reportedly stepped into the vacuum – in effect capturing roles such as coolies, helpers, domestic workers, vendors, ragpickers and construction labourers.
The report argues that these workers accept significantly lower wages and poorer conditions, thereby depressing wage levels across the informal sector and displacing natives from jobs they once dominated.
Key informants link this trend directly to rising resentment among poor local communities, who see themselves competing with people who neither pay taxes nor carry the same legal burdens.
Beyond low‑end labour, the report places illegal migrants squarely inside Mumbai’s shadow and black economy.
They are said to be embedded in smuggling chains (gold, arms, narcotics), illicit liquor, hawking networks, unlicensed workshops, illegal transport and the sex trade.
Because much of this activity is unregistered, it yields no tax revenue but fuels parallel power structures in slums and industrial pockets.
The Remittance Outflow: Money Earned in India, Parked Abroad
The report repeatedly flags remittances as a critical but under‑discussed dimension.
In the executive findings, it is stated that about 40% of immigrants remit between ₹10,000 and ₹1,00,000 per month to their home countries.
Chapter 7 of the report on the economic activities of the illegal Bangladeshis and Rohingyas notes that nearly 84% of surveyed migrants send money back home regularly, characterising these flows as largely unrecorded and outside formal banking channels.
Despite low declared incomes, many respondents report owning land, houses, livestock or vehicles in Bangladesh or Myanmar, which the study interprets as proof that significant earnings made in Mumbai are being converted into assets abroad rather than reinvested locally.
The authors frame this as a “loss of revenue” and a silent economic drain: the city bears the cost of infrastructure, health, policing and subsidies, while a sizeable share of the surplus is exported out of India.
Women, Sex Work And The Dark Underside of “Survival”
Gender emerges as a particularly grim axis in the report, which devotes extensive space to the condition of illegal migrant women.
The executive summary states that more than 50% of the women interviewed are involved in prostitution. Many women are described as living “dual lives”: working as domestic helpers, vendors, cleaners or casual labourers by day and as sex workers by night to support families locally and back home.
Focus group discussions and key informant interviews point to brothel‑based and street‑based sex trade in areas like Kamathipura and certain slum pockets, where Bangladeshi and Rohingya women are allegedly controlled by brokers, pimps and local criminal elements.
This not seen not only as a moral and legal crisis, but as the nucleus of a wider criminal ecosystem. Human trafficking, forced prostitution, minor girls pushed into sex work, and cross‑border rackets are repeatedly flagged.
These networks link illegal immigration directly to organised crime, corruption among officials, and the funding of other illegal activities including smuggling.
Public Services Under Siege
Another major strand in the study is the pressure on already overstretched public infrastructure.
Public healthcare: Around four‑fifths of surveyed immigrants reportedly use government hospitals, dispensaries and primary health centres despite lacking full documentation. The authors argue that this adds to congestion, long queues and overstretched staff, effectively crowding out poor Indian citizens who rely on the same facilities.
Overcrowding and disease: Slums dominated by illegal migrants are often characterised by high density, kuchha or semi‑pucca housing, narrow lanes, open drains, poor solid waste management and contaminated water sources.
Localities such as Govandi and Mankhurd are specifically named as examples where schools, electricity supply, and water systems are under visible strain.
The study ties these conditions to increased risk of infectious diseases, chronic illness and frequent outbreaks, making immigrant‑dense areas potential public health hotspots.
Crime, Drugs And “No‑Entry” Zones
The report is blunt in linking illegal migration to rising crime and law‑and‑order problems, especially in certain pockets. Key informant interviews speak of illegal migrants’ involvement in arms and gold smuggling, counterfeit currency, and above all, narcotics.
Particular concern is voiced about drug peddling targeting school and college students in areas like Govandi, Kurla and Malad, where cheap substances are allegedly sold by migrant-linked networks.
The report presents a schematic “vicious cycle of crime”: illegal entry → settlement in slums → recruitment by gangs and touts → involvement in black economy → localised spikes in crime, especially against women and children.
Law enforcement, the study argues, is simply not equipped to police dense, informally built, socially closed localities where residents lack documentation and can vanish or relocate quickly.
Many such areas are described as de facto “no‑entry” zones for outsiders, where local gangs and community leaders exercise more real power than the state.
The report states that this environment also makes it easier for extremist elements and radical preachers to operate, recruiting from a pool of young men with no stake in the formal system.
Radicalisation And National Security
Going beyond street‑level crime, the authors point to illegal migration as a national security problem. They note that security agencies have increased surveillance of certain pockets due to suspected links between some illegal immigrants and extremist or Islamist groups.
When we consider global examples such as Germany, France and debates with regard to Muslim migration. When placed alongside Indian cases like PFI, it is derived that demographic shifts combined with ghettoisation can fuel radicalisation.
The report warns that coastal and port‑adjacent migrant settlements in Mumbai pose special risks: they can serve as logistical hubs for cross‑border smuggling and potential terror operations targeting financial and strategic infrastructure.
In this telling, ignoring illegal migration is not just lax governance but a direct compromise of internal security and national sovereignty.
Vote‑bank Politics And Erosion Of Native Voice
A central political alarm in the report is the link between illegal migration and electoral manipulation.
India’s fragmented documentation system, multiple IDs such as voter card, Aadhaar, ration card, PAN, birth certificates are identified to be fertile ground for fraud.
The absence of a single, non‑duplicable citizenship document allows illegal immigrants, once settled, to obtain forged or “managed” papers, enter voter lists and access welfare schemes meant for citizens.
Key informants allege that local political actors, cutting across parties, protect these populations in exchange for loyal vote banks, especially in closely contested municipal wards and assembly segments.
The report argues that this has two corrosive effects.
First, it undermines electoral integrity, what it calls “shadow voting”, where non‑citizens influence political outcomes.
Second, it dilutes the political voice of original residents, including Koli communities and Marathi‑speaking natives, who find themselves numerically and politically marginalised in their own neighbourhoods.
The study links this to a broader cultural anxiety: Illegal immigration can possibly lead to eroding the Marathi and original Mumbaikar identity, not only through demographic change but through shifting political priorities and public symbolism.
Governance Paralysis And Distorted Planning
Beyond politics, the presence of a large undocumented population is said to distort the basic instruments of governance.
Census and survey data do not fully capture illegal immigrants, but their physical presence still consumes water, housing, roads, transport and welfare resources.
This mismatch between official numbers and actual demand leads to chronic under‑provision and misallocation, especially in slum‑heavy wards.
Planners struggle to design infrastructure projects – housing, sewage, transport, because the real user base is far larger and more fluid than what official data suggests.
The report states that this fuels a cycle where:
Overburdened systems fail → native taxpayers blame “the government” and “outsiders” → politicians tighten rhetoric but avoid hard action due to vote‑bank calculations → illegal settlements are quietly regularised or ignored → networks strengthen further.
Frequent relocations by immigrant families from one slum to another, from one rented room to another are also flagged as destabilising for local communities, schooling continuity and social cohesion.
Housing, Rents and Urban Chaos
Housing is another flashpoint.
The report notes that demand for ultra‑low‑cost housing from illegal immigrants intensifies pressure on slums and informal settlements, accelerating unauthorized construction and vertical expansion of already unsafe structures.
This, in turn, pushes up rents in lower‑income segments, making basic housing unaffordable for many poor citizens.
Informal settlements grown around migrant clusters disrupt urban planning, encroach on public land and infrastructure corridors, and complicate future redevelopment.
Public transport such as trains, buses, shared autos is also described as overwhelmed, with illegal migrants adding to already crushing peak‑hour loads.
Social Cohesion, Mistrust and Rising Nationalism
Socially, the report argues that illegal migration is deepening fault lines rather than healing them.
Many immigrant clusters are ethnically and religiously homogeneous, with limited contact with surrounding populations, leading to “us vs them” perceptions on both sides.
Competition for scarce jobs, rations, school seats, hospital beds and municipal services fuels resentment and periodic clashes.
The study notes rising nationalist sentiment and polarised debates on immigration, with frequent accusations that political parties are “selling” citizenship benefits and local resources in exchange for captive vote banks.
Rather than dismiss this as mere rhetoric, this can be seen as a predictable social response to sustained, unaddressed demographic and economic disruption.
What the Report Implicitly Demands
The report does call for strong state action given the findings.
It mentions the NRC and broader citizenship debates as responses to the scale of illegal immigration and associated security concerns.
It argues that effective measures, tightened border control, efficient identification mechanisms, deportation protocols, and firm diplomatic engagement with source countries, are essential to protect national sovereignty and citizens’ rights.
It warns that continued inaction will further erode public trust in institutions, deepen social tensions, and leave cities like Mumbai vulnerable to crime, radicalisation and political capture.
Overall, the report documents how illegal immigration, aided by porous borders, compromised politics and ideological denial, is silently rewriting Mumbai’s demography, economy and power structures.
It invites a hard question: if this is what one city already looks like, what happens if the same patterns play out, unchecked, across India’s other urban centres?
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