No one-time password is needed to unlock an Electronic Voting Machine, PTI quoted the returning officer of the Mumbai North-West Lok Sabha constituency as saying on Sunday.

The official was responding to a newspaper report claiming that the brother-in-law of Ravindra Waikar, the newly-elected MP from the constituency, had taken a phone to the vote counting centre on June 4 that was “used for generating the OTP [one-time password] that unlocked the EVM machine”.

“The EVM is a standalone system and there is no need for an OTP [one-time password] to unlock it,” PTI quoted Vandana Suryavanshi, the returning officer, as saying at a press conference. “It is not programmable and has no wireless communication capabilities.”

The police on Wednesday filed a case against Mangesh Pandilkar, Waikar’s brother-in-law, for allegedly taking a mobile phone to a counting centre on the day of the Lok Sabha election results.

The police booked Pandilkar under the Representation of the People Act and Section 188 of the Indian Penal Code, which pertains to disobeying official orders.

After the case against Pandilkar was filed, the police collected security camera footage from the counting centre. An inquiry reportedly showed that he did not have permission to take a phone into the area.

On Sunday, Suryavanshi said that the personal phone of Dinesh Gurav, the data entry operator of the Jogeshwari Assembly segment, was found with an unauthorised person and that action is being taken in the matter.

“Data entry and vote counting are two different aspects,” Suryavanshi said, according to PTI. “An OTP enables the ARO [assistant returning officer] to open the ENCORE login system for data entry. The counting process is independent and has nothing to do with unauthorised use of mobile phone, which is an unfortunate incident and is being probed.”

ENCORE is an online application used by poll officials during the election process.

“Advance technical features and robust administrative safeguards are in place to rule out any possibility of manipulation,” Suryavanshi added. “Safeguards include conducting everything in the presence of candidates or their agents.”

On Sunday, the police also said that the case involving Gurav and Pandilkar is under investigation. The police added that they had not released any information about the phone being allegedly used to unlock the voting machine, as claimed by the newspaper report, to any publication.

Waikar, a member of Maharashtra Chief Minister Eknath Shinde-led Shiv Sena faction, won the Mumbai North-West seat by defeating Amol Kirtikar of the Shiv Sena (Uddhav Balasaheb Thackeray) on June 4.

While initially it appeared that Kritikar had won, Waikar demanded the recounting of votes as the margin of victory was narrow. After recounting the votes polled with the Electronic Voting Machines, it was found that Kritikar had one more vote as compared to Waikar. However, re-checking the postal ballots placed Waikar ahead by 48 votes.

Waikar was eventually declared the winner, in what was the closest contest in the general election.

However, after the results, Kirtikar as well as other defeated candidates alleged irregularities in the counting process.

Kirtikar had alleged that while election officials had been announcing the number of votes polled after each round till the 19th cycle of counting, they stopped doing so afterwards.

Watch: Indian elections: How secure is the EVM-VVPAT process?