Delhi's Battle Against Duplicate Images in Public Records: How It Stacks Up Against Mumbai, London and Seoul

Delhi's land registry offices processed more than 1.4 million property document scans in the financial year ending March 2026, and a significant share of those files contained duplicate image attachments — identical photographs, recycled identity scans, or copy-pasted utility bills inserted to bulk out submissions. The problem is not new, but civic technology officers at the Delhi Development Authority have escalated it to a formal audit exercise this year, targeting specifically the digitisation backlog inherited from Sub-Registrar offices across all 11 revenue districts.

The timing matters. Delhi is midway through a court-mandated overhaul of its Yamuna floodplain land records, ordered by the National Green Tribunal in a series of hearings that concluded in early 2026. Duplicate image files have repeatedly delayed the verification of encroachment cases along the river's eastern bank, particularly in areas like Usmanpur and Geeta Colony. When the same photograph appears against two separate property parcels — sometimes kilometres apart — it stalls compensation decisions and muddies ownership chains that officials were already struggling to reconstruct.

What Delhi Is Actually Doing

The DDA launched its Duplicate Digital Asset Removal Protocol in February 2026, assigning a dedicated team within its IT wing at Vikas Sadan in INA Colony to run hash-matching software across scanned document repositories. The protocol cross-references image fingerprints — cryptographic checksums generated from each file — against a central database. Files that share an identical checksum are flagged for human review before being removed or merged. The Delhi Municipal Corporation's property tax portal, which covers around 1.8 million registered properties in the city, began a parallel exercise in April 2026 under its GIS cell based in Civic Centre, Minto Road.

Neither exercise is complete. Officials familiar with the process, speaking in their institutional capacity, have acknowledged to The Daily Delhi that the backlog of unreviewed flagged files runs into tens of thousands as of this month. The core difficulty is not the technology — hash-matching is computationally cheap — but the downstream legal question: once a duplicate is confirmed, which record is authoritative? That decision requires a revenue officer's sign-off, and Delhi's Sub-Registrar offices are chronically understaffed.

How Other Cities Are Managing the Same Problem

Mumbai's Maharashtra Land Records Department completed a comparable deduplication sweep of its city survey records in late 2024, working through a contract with the National Informatics Centre. Mumbai's urban land database is smaller by record count but more complex by ownership fragmentation, particularly in areas like Dharavi and the Bandra-Kurla Complex. The Maharashtra government has publicly reported that the sweep identified duplicated images in roughly 3 percent of scanned files, though the figure applied specifically to post-2018 digitisation batches.

London's Land Registry — which maintains the most digitised property record system among major global capitals — has operated automated duplication checks as a standard intake filter since 2019. Every document submitted to HM Land Registry's portal in the United Kingdom passes through an automated integrity check before human caseworkers touch it. Seoul's Ministry of Land, Infrastructure and Transport introduced a similar front-end validation layer in 2021 as part of South Korea's broader Smart City Data Hub initiative, which covers 25 metropolitan districts.

Delhi is doing the reverse: cleaning up after the fact rather than filtering at the point of entry. That distinction is significant. Retrospective deduplication is slower, more expensive per file, and more legally contentious. The DDA's Vikas Sadan team is essentially auditing decisions already encoded into official records, some of them years old.

The practical consequence for ordinary Delhiites is most visible in Rohini and Dwarka, two of the city's largest planned residential sectors, where property mutation applications have been held in administrative limbo while image audits catch up. Residents who filed for ownership transfer in late 2025 have been told informally to expect delays of three to four additional months. Whether the DDA meets its stated target of clearing the backlog before the next monsoon-season filing rush — typically peaking in September — will depend on whether the revenue officer cadre receives the reinforcements the agency has been requesting since January.