The Central Bureau of Investigation (CBI) is India's premier investigative police agency, operating under the jurisdiction of the Ministry of Personnel, Public Grievances and Pensions. It is not a statutory body but an institution that derives its investigative authority from the Delhi Special Police Establishment (DSPE) Act, 1946. The CBI traces its origin to the Special Police Establishment (SPE), which was constituted in 1941 during World War II to investigate bribery and corruption in war-related procurements. The SPE was formalized by the DSPE Act, 1946, and the CBI itself was established in 1963 by a resolution of the Ministry of Home Affairs, following the recommendation of the Santhanam Committee on Prevention of Corruption (1962–1964), to investigate serious crimes like corruption, economic offenses, and inter-state cases.
The mechanism of the CBI is governed by the DSPE Act, 1946, which grants its officers police powers. Crucially, under Section 6 of the Act, the CBI requires the prior consent of a State Government to investigate a case within that state, as policing is a State subject under the Constitution. This consent can be 'general' or 'specific,' but the Supreme Court and High Courts can direct the CBI to investigate a crime anywhere in the country without the state's consent.
The CBI connects to several key concepts and institutions, including the Central Vigilance Commission (CVC), which supervises the CBI's investigation of offenses under the Prevention of Corruption Act. The Lokpal and Lokayuktas Act, 2013, significantly changed the appointment process for the CBI Director by introducing a high-level committee consisting of the Prime Minister, the Leader of the Opposition, and the Chief Justice of India or a Supreme Court judge. Recently, the Delhi Special Police Establishment (Amendment) Act, 2021, amended the fixed two-year tenure for the CBI Director, allowing for extensions up to a total of five years. Furthermore, the Supreme Court's judgment in Vineet Narain vs. Union of India (1997) mandated a fixed tenure for the CBI Director to ensure independence.