Rajasthan’s Anti-Corruption Bureau on Sunday registered an FIR against Union minister Gajendra Singh Shekhawat, among others, in connection with the alleged conspiracy to bring down the Congress government, prompting the party to demand his immediate resignation or removal to ensure a fair investigation.

Minister for water resources (Jal Shakti) Shekhawat’s name had cropped up in connection with audio tapes that the Congress has cited as evidence of the conspiracy to destabilise the Ashok Gehlot government. The conversations in the tapes suggest horse-trading deals with Congress rebels. Shekhawat has denied that the voice in the tapes is his.

ACB director-general Alok Tripathi said the FIR had been registered under the Prevention of Corruption Act on a complaint by Congress chief whip Mahesh Joshi on Friday.

In the FIR, details of purported conversations of rebel Congress MLA Bhanwarlal Sharma with Sanjay Jain and Shekhawat are mentioned. While the Congress has alleged that Jain is a BJP leader, the BJP has denied the claim.

“We will send the audio clips to the Forensic Science Laboratory for testing,” Tripathi said. Jain is already in police custody.

Congress spokesperson Ajay Maken said Shekhawat should resign and join the investigation. “It will be difficult for the police to freely inquire into his role as long as he remains a central minister. If he doesn’t relinquish office on his own, the Prime Minister should sack him for the sake of justice.”

Maken added: “Shekhawat is saying it is not his voice in the recordings. Why is he then afraid of giving his voice sample? Nobody is above the law. It is good for him to clear his name in the sinister conspiracy of destabilising a government by using money if he is not involved. While he has lost the moral right to continue in the government, it has been the tradition for ministers to resign till investigations are complete.”

Referring to the Union home ministry’s decision to seek a report on the phone-tapping episode and the threat to hand over the investigation to the CBI, Maken said: “Is the CBI being brought in to save the bigger people whose names may crop up during the investigation into the plot to buy MLAs? The Centre should stop giving threats and allow the investigation to be completed.

“The BJP should also tell the nation where from the black money to buy MLAs is coming. Huge sums of Rs 30-35 crore per MLA is being talked about. Does the Centre not want the people involved in such a huge operation to pull down the government to be exposed?”

The Congress spokesperson accused the police in Haryana and Delhi of obstructing Rajasthan police from collecting the voice samples of the accused.

“If the BJP and the central government are not involved, why are the income tax (department), the Enforcement Directorate, Haryana and Delhi police being deployed in the operation and to give protection to rebel Congress MLAs? Every day new layers of conspiracy and involvement of the BJP are unravelling. The people of Rajasthan will not forgive the conspirators,” Maken said.

Alleging that the real mastermind of the operation was the BJP leadership, the Congress leader said: “The Special Operations Group (SOG) team was stopped outside the hotel in Manesar and the (rebel) MLAs were allowed to sneak out. Now we hear they have been put up in a Delhi five-star hotel. Isn’t it amazing that the police of a BJP-ruled state and the central government are creating hurdles in the investigation into the conduct of Congress MLAs?”

Congress communications chief Randeep Surjewala again asked sacked deputy chief minister Sachin Pilot and his supporters to reject the BJP’s hospitality and return to Rajasthan if their claim of still being in the Congress had any meaning. Asserting that the Congress had majority in Rajasthan, Surjewala said: “BJP leaders have also realised that the plot has failed and they don’t want a floor test anymore. We request the BJP to free our MLAs and let them return to the family.”

Rajasthan High Court will on Monday morning resume hearing on the plea of the Pilot camp against the disqualification proceedings against the rebel MLAs. Even if the high court prevents disqualification, the Congress plans to call the Assembly immediately and take a trust vote.

If the dissenting MLAs vote against the government, they will be disqualified. The Congress wants the membership of these MLAs to be scrapped to prevent another round of conspiracy to topple the government.