The ruling BJP in Karnataka has been accused of getting an NGO to fraudulently collect Bangalore voters’ caste data and other details so it could tailor its campaign for the upcoming civic polls to an area’s demography, and selectively delete names from the rolls.

The Congress has alleged that people hired by the NGO conducted the door-to-door data collection drive with fake identity cards, trying to gain the voters’ trust by masquerading as civic employees.

The Opposition party says that 6 lakh genuine voters’ names have been erased from the rolls following the exercise — a claim denied by the city civic body, Bruhat Bengaluru Mahanagara Palike, which had commissioned the drive by the Chilume Educational Cultural and Rural Development Institute.

Bangalore has 79 lakh voters, according to official data. Congress MLA Rizwan Arshad told The Telegraph that a Krishnappa Ravikumar got the NGO registered in 2013 and also runs the “Chilume Enterprises Private Limited that does election-related work for the BJP”.

The Congress has alleged that the NGO conducted the drive without charging any fees. Karnataka chief electoral officer Manoj Kumar Meena has ordered an investigation. Chief minister Basavaraj Bommai has denied any wrongdoing and accused the Congress of being “bankrupt of ideas” ahead of the civic polls, due in a couple of months, and the Assembly elections next summer.

The civic body, whose commissioner is the district election officer, stopped the drive after the controversy broke this week. Special civic commissioner S. Rangappa said that not a single voter’s name had been deleted fraudulently and that “whatever deletion has happened is owing to normal circumstances such as duplication or death”.

Bommai said NGOs had been hired for the Systematic Voters Education and Electoral Participation (SVEEP) — a door-to-door drive conducted regularly across the country under the supervision of the Election Commission to build voter awareness and revise electoral rolls — “even before 2018”, implying past Congress governments had done it too.

A retired Election Commission official, who spoke to this newspaper on the condition of anonymity, expressed surprise at the comment. He said the SVEEP is expected to be conducted by designated booth-level officers (BLOs) who are “government employees such as schoolteachers, quasi-government staff such as local body employees, and retired government officials”.

He added that the SVEEP is meant to verify only basic details such as name, age, address, gender and the name of the father or husband, and certainly not caste identities.

Media reports say the NGO workers asked the voters’ caste, mother tongue, marital status, educational and employment status, Aadhaar and voter card numbers, email address and phone numbers, as well as their opinion on the performance of their elected representatives.

Collection of such details by a private agency may raise questions about a possible breach of privacy.

According to the Congress, the extra data collected during the drive has been uploaded on Sameeksha, a private mobile app accessible only to those authorised by the NGO. The NGO’s Bangalore office was shut and none from the organisation could be reached for comments.

The Congress has said the NGO’s workers were provided with fake identity cards that declared them BLOs and carried the civic body’s insignia.

Each “BLO” was allegedly paid a monthly wage of about Rs 15,000 plus a possible bonus.