Investigation
Also called: Police investigation
All proceedings under the BNSS for the collection of evidence by a police officer, or by a person other than a Magistrate authorised by a Magistrate.
Explained
Section 2(1)(l) of the BNSS provides that investigation includes all the proceedings under the Sanhita for the collection of evidence conducted by a police officer or by any person, other than a Magistrate, who is authorised by a Magistrate in this behalf. The definition repeats Section 2(h) of the CrPC, which applied earlier, and adds an Explanation that where a special Act is inconsistent with the Sanhita, the special Act prevails. Special laws such as the PMLA have their own definitions; Section 2(1)(na) of the PMLA gives the Director and authorised authorities the power to investigate under that Act.
Investigation is the work of the police, and a Magistrate can never conduct it personally. It begins on information under Section 173 or on reasonable suspicion under Section 176, and usually covers proceeding to the spot, ascertaining the facts, discovering and arresting the suspect, and collecting evidence by examining persons (Section 180), searching and seizing. It ends with the report under Section 193(3), which must be completed without unnecessary delay, and within two months for the sexual offences listed in Section 193(2).
Investigation must be distinguished from inquiry and trial. An inquiry under Section 2(1)(k) is conducted by a Magistrate or Court and is not a trial, while investigation is conducted by the police before the case reaches the court. In a non-cognizable case the police may investigate only on a Magistrate's order (Section 174(2)), and they then have every power of investigation except arrest without warrant.
Courts protect the integrity of investigation without taking it over. A constitutional court may transfer an investigation to the CBI or monitor it, but it does not direct how it is to be done, and its role ends once the charge sheet is filed. The protection against self-incrimination in Article 20(3) applies from the stage of police interrogation, so compelled narcoanalysis or polygraph tests are barred.
What the law says
(l) “investigation” includes all the proceedings under this Sanhita for the collection of evidence conducted by a police officer or by any person (other than a Magistrate) who is authorised by a Magistrate in this behalf.
Explanation.—Where any of the provisions of a special Act are inconsistent with the provisions of this Sanhita, the provisions of the special Act shall prevail;
Clause (l) of sub-section (1) defines investigation; clause (k) defines inquiry
Earlier law: CRPC 2. Definitions.
(a) when information as to the commission of any such offence is given against any person by name and the case is not of a serious nature, the officer in charge of a police station need not proceed in person or depute a subordinate officer to make an investigation on the spot;
(b) if it appears to the officer in charge of a police station that there is no sufficient ground for entering on an investigation, he shall not investigate the case:
Provided further that in relation to an offence of rape, the recording of statement of the victim shall be conducted at the residence of the victim or in the place of her choice and as far as practicable by a woman police officer in the presence of her parents or guardian or near relatives or social worker of the locality and such statement may also be recorded through any audio-video electronic means including mobile phone.
Procedure for investigation by the officer in charge of a police station
Earlier law: CRPC 157. Procedure for investigation.; 157(1); 157(2); New Sub-Section
(3) Any police officer receiving such order may exercise the same powers in respect of the investigation (except the power to arrest without warrant) as an officer in charge of a police station may exercise in a cognizable case.
(4) Where a case relates to two or more offences of which at least one is cognizable, the case shall be deemed to be a cognizable case, notwithstanding that the other offences are non-cognizable.
Investigation of non-cognizable cases only on a Magistrate's order
Earlier law: CRPC 155. Information as to non-cognizable cases and investigation of such cases.
(1) Every investigation under this Chapter shall be completed without unnecessary delay.
(2) The investigation in relation to an offence under sections 64, 65, 66, 67, 68, 70, 71 of the Bharatiya Nyaya Sanhita, 2023 or under sections 4, 6, 8 or section 10 of the Protection of Children from Sexual Offences Act, 2012 shall be completed within two months from the date on which the information was recorded by the officer in charge of the police station.
(3) (i) As soon as the investigation is completed, the officer in charge of the police station shall forward, including through electronic communication to a Magistrate empowered to take cognizance of the offence on a police report, a report in the form as the State Government may, by rules provide, stating—
Report of the police officer on completion of investigation
Earlier law: CRPC 173. Report of police officer on completion of investigation.
[(na) “investigation” includes all the proceedings under this Act conducted by the Director or by an authority authorised by the Central Government under this Act for the collection of evidence;]
Separate definition of investigation under the PMLA
Earlier law: Section 2, CrPC
For the exam
- Definition: Section 2(1)(l) BNSS, earlier Section 2(h) CrPC; a Magistrate cannot investigate.
- Explanation to Section 2(1)(l): an inconsistent special Act prevails over the BNSS.
- Investigation (police) differs from inquiry (Magistrate or Court) and trial.
- Non-cognizable case: investigation only on a Magistrate's order, and no arrest without warrant.
- Investigation ends with the police report under Section 193(3) BNSS.
791 questions in the Law Maker question bank use this term. Practise Bharatiya Nagarik Suraksha Sanhita questions
Judgments
- State of West Bengal v. Committee for Protection of Democratic Rights (2010)A High Court under Article 226 may direct the CBI to investigate a cognizable offence in a State without that State's consent; this neither violates the federal structure nor separation of powers, but the power must be used sparingly.
- Vineet Narain v. Union of India (1997)The Court struck down Directive No. 4.7(3) of the Single Directive, which required prior sanction before the CBI inquired into senior officers, and issued binding directions under Articles 32 and 142 to insulate investigating agencies.
- Nandini Satpathy v. P.L. Dani (1978)The Court held that Article 20(3) and Section 161(2) CrPC protect an accused during police interrogation, cover exposure to other pending or imminent charges, and bar psychologically compelled answers; the Section 179 IPC prosecution was quashed.
- Selvi v. State of Karnataka (2010)Compulsory narcoanalysis, polygraph and BEAP tests violate Article 20(3) and Article 21; no one may be forcibly subjected to them, and even voluntary test results are inadmissible, though facts later discovered may be proved under Section 27.
Related terms
- InquiryUnder Section 2(1)(k) of the BNSS, every inquiry, other than a trial, conducted under the Sanhita by a Magistrate or Court.
- Police reportThe report that the officer in charge of a police station forwards to a Magistrate under Section 193(3) of the BNSS when an investigation is completed.
- Cognizable offenceAn offence for which a police officer may arrest without warrant, in accordance with the First Schedule to the BNSS or any other law in force.
- Non-cognizable offenceAn offence for which a police officer has no authority to arrest without warrant. A case involving such an offence is a non-cognizable case.
- ChargeThe formal written statement of the offence an accused is to be tried for, with particulars of time, place, person and manner, so that he knows exactly what case he must meet.
Further reading
Checked 6 November 2026. Statutory text is quoted from the Bare Acts library, taken from India Code. See the full glossary.