The 2G spectrum case was an alleged scam by the politicians and government officials under the United Progressive Alliance (Congress) coalition government.
The Central Bureau of Investigation (CBI) court on Dec 21, 2017 declared no evidence to prosecute the accused and acquitted all accused personnels.
The Union Government of that time was accused of undercharging mobile telephone companies for frequency allocation licenses, which they used to create 2G spectrum subscriptions for cell phones. The Government chose NM Rothschild & Sons to design a first-of-its-kind e-auction mechanism in the world, a US$2.27 billion landmark deal. The difference between the money collected and that mandated to be collected was estimated by the Comptroller and Auditor General of India at ₹1.76 trillion (US$28 billion), based on 2010 3G and BWA spectrum-auction prices. In a chargesheet filed on 2 April 2011 by the Central Bureau of Investigation (CBI), the loss was pegged at ₹309,845.5 million (US$4.9 billion). In a 19 August 2019 reply to the CBI, the Telecom Regulatory Authority of India (TRAI) said that the government had gained over ₹30 billion (US$470 million) by selling 2G spectrum.
On 2 February 2012, the Supreme Court of India ruled on a public interest litigation (PIL) related to the 2G spectrum allocation. The court declared the allotment of spectrum "unconstitutional and arbitrary", cancelling the 122 licenses issued in 2008 under A. Raja (Minister of Communications & IT from 2007 to 2009), the primary official accused. According to the court, Raja "wanted to favour some companies at the cost of the public exchequer" & "virtually gifted away important national asset[s]." The zero-loss theory was discredited on 3 August 2012 when, after a Supreme Court directive, the Government of India revised the base price for 5-MHz 2G spectrum auctions to ₹140 billion (US$2.2 billion), raising its value to about ₹28 billion (US$440 million) per MHz (near the Comptroller and Auditor General estimate of ₹33.5 billion (US$530 million) per MHz).