In the city’s two election districts, 64% of voters under adjudication were deleted in Calcutta North, compared with 36% in Calcutta South, data shared by Election Commission sources showed.

The stark difference in deletion rates between the two parts of the city has raised eyebrows among political workers and analysts.

Some attributed the higher percentage in the north to the presence of more minority-dominated neighbourhoods.

A Calcutta-based research institute suggested that north Calcutta’s large population of migrant workers may explain some of the deletions. Many migrants may have failed to submit adequate documents during SIR hearings or were registered voters elsewhere.

Calcutta North comprises seven Assembly constituencies: Entally, Chowringhee, Beleghata, Maniktala, Jorasanko, Shyampukur and Cossipore-Belgachia.

Calcutta South has four: Ballygunge, Bhabanipur, Rashbehari and Calcutta Port.

In south Calcutta, 28,468 of the 78,657 under adjudication were deleted. Of the 61,236 voters under adjudication in north Calcutta, 39,164 were deleted.

While the difference in absolute numbers is not that stark, the percentage has drawn attention.

“During our field study, we found that north Calcutta has a large number of single male migrants who may have failed to submit adequate documents. This could be one of the reasons why the percentage of those under adjudication is so high in the north,” said a researcher at Sabar Institute, a Calcutta-based organisation studying patterns of deletion in the contentious SIR.

In Shyampukur, 2,081 of the 2,759 voters under adjudication were deleted — about 75%. In Jorasanko, over 3,500 out of 5,652 under adjudication were struck off, roughly 62%. In Cossipore-Belgachia, 3,008 of 5,602 voters under adjudication were deleted, around 53%.

“I am shocked at how many genuine voters have been deleted. I have known some of them for decades. The families have lived here for generations,” Shashi Panja, Trinamool’s sitting MLA and candidate from Shyampukur, told Metro on Wednesday.

A Trinamool leader managing campaigning in north Calcutta said there were pockets with dense minority populations, including areas around MG Road, Zakaria Street, Rajabazar and multiple neighbourhoods of Entally, Chowringhee and Belgachia.

Critics of the SIR have alleged that the exercise disproportionately excluded Muslim voters.

An earlier study flagged an alarming disproportionality between the Muslim share of the electorate and their share among deleted voters in Nandigram, the East Midnapore Assembly seat represented by BJP leader Suvendu Adhikari.

An official at the office of Bengal’s chief electoral officer said the difference could be attributed to voters failing to provide the correct documents: “Judicial officers decided the cases based on whether the voters had submitted the right documents. It could be that most of the voters failed to submit the right documents.”