The National Investigation Agency (NIA) was established under the NIA Act, 2008 to investigate and prosecute offenses that affect the sovereignty, security, and integrity of India. The Act provides the legal framework for the agency’s constitution, powers, and jurisdiction.
Scope of the NIA under the NIA Act, 2008:

1. Jurisdiction & Applicability
• The NIA has jurisdiction across India, and, after the 2019 amendment, it can investigate offenses committed outside India as well if they are against Indian citizens or affecting Indian interests.
• The Act overrides any other law in force for investigation and prosecution of scheduled offenses.

2. Scheduled Offenses
The NIA is empowered to investigate specific offenses listed in the Schedule of the Act, which includes:
• Offenses under the Unlawful Activities (Prevention) Act, 1967 (UAPA)
• Atomic Energy Act, 1962
• Anti-Hijacking Act, 2016
• Anti-Piracy laws
• Explosive Substances Act, 1908
• Weapons of Mass Destruction Act, 2005
• Terrorist activities, cyber terrorism, and crimes with cross-border implications
The Schedule can be expanded by the central government as needed.
3. Powers of Investigation
• The NIA has all the powers of a police officer under the Code of Criminal Procedure (CrPC), 1973.
• It can search, seize, arrest, and prosecute suspects involved in scheduled offenses.
• It can take over investigations from state police forces if the central government deems it necessary.

4. Role of Central and State Governments
• State governments are required to inform the Central Government about scheduled offenses.
• The Central Government may direct the NIA to investigate such offenses, even without the state’s consent (especially after the 2019 amendment).
• State police can continue parallel investigations but the NIA’s probe will take precedence.

5. Special NIA Courts
• The Act provides for the establishment of Special Courts for the trial of scheduled offenses.
• These courts are appointed by the Central Government in consultation with the Chief Justice of the High Court.
• They ensure speedy trial and special handling of sensitive cases.

6. Extra-Territorial Jurisdiction (Post-2019 Amendment)
• The NIA can investigate offenses committed outside India, provided they are linked to Indian interests, nationals, or institutions.
• Investigations abroad require cooperation with foreign governments and must comply with international law.
Conclusion
The NIA Act, 2008, grants the NIA wide-ranging powers to handle terrorism and other offenses threatening national security. Its scope has expanded over time, particularly with the 2019 amendment, which reinforced its autonomy, extra-territorial reach, and primacy over state-level investigations in matters of national importance.

The NIA is empowered under Section 3 of the Act to investigate and prosecute offences listed in the
Schedule, including terrorism, arms trafficking, and offenses under the UAPA. Its jurisdiction was expanded in
2019 to include crimes committed outside India involving Indian citizens or interests.