The Home Ministry said on Sunday that it had been ten days since it ordered an investigation into the alleged phone tappings of ministers and businessmen carried out by the Essar Group, following a report in The Indian Express that a complaint was filed with the Prime Minister's Office on the matter. The ministry also said that the report of the inquiry will be forwarded to Prime Minister Narendra Modi, according to NDTV.

The complaint to the PMO was filed by a former employee, Albasit Khan, of the multinational conglomerate, who reportedly oversaw the whole process carried out between 2001 and 2006. In the 29-page complaint submitted on June 1, 2016, Khan's lawyer Suren Uppal said the recorded conversations indicate “corruption in the business milieu” and a nexus between businesses and the government.

According to Uppal, Essar’s Prashant Ruia and Ravikant Ruia asked Khan, who was the head of the company's security, to tap the phones in 2001. They allegedly told him that since as the company was a telecom licensee it was required by the government to help in investigations by intercepting and tapping phones that are under State surveillance.

However, Khan has gone undercover and not spoken up about this so far, Uppal said. People whose phones were allegedly tapped include Railway Minister Suresh Prabhu, former ministers Praful Patel and Ram Naik, and the Ambani brothers Mukesh and Anil, among other top ministers and banking heads.

Opposition parties have lapped up the controversy, with the Congress, AAP and Janata Dal (United) criticising the National Democratic Alliance government, which was in power between 1999 and 2004, saying it was compromised. The United Progressive Alliance was elected to power in 2004.

Congress spokesperson Manish Tewari said the budget, telecom policy, disinvestment processes, ministerial appointments, parliamentary committee goings-on and “allegedly even criminal investigations involving influential ministers in the then government were also fixed”.

On Saturday, AAP demanded that the tapes be made public. “These tapes barring a few matters, which are related to the security and sovereignty, should be made public so that the whole country knows how the systems are manipulated by few industrial houses and how the politicians, the judges and the Supreme Court are being manipulated,” party leader Ashutosh said.

Anil Ambani's ADA Group in a statement said, “We are shocked at news reports on the so called 'Essar Tapes' that refer to the completely illegal and criminal tapping of phones of some individuals in our group, allegedly done by vested interests more than 10-15 years ago, in the period prior to the reorganisation of the Reliance Group.