The Supreme Court’s ruling in Amlesh Kumar v. State of Bihar (2025) has reaffirmed a core constitutional principle: forced or involuntary narco-analysis tests violate fundamental rights. By setting aside a Patna High Court order, the apex court underscored that investigative convenience cannot override constitutional safeguards laid down earlier in Selvi v. State of Karnataka (2010).
What the Supreme Court held
The Supreme Court ruled that any narco test conducted without the free and informed consent of the accused is unconstitutional. The Court found that the High Court’s order permitting such a test ignored binding guidelines from Selvi, which clearly prohibit involuntary administration of narco-analysis, polygraph, or brain-mapping tests.
The judgment reinforces that constitutional protections under Articles 20 and 21 are non-negotiable, even at the investigative stage.
What is a narco test?
A narco test is an investigative technique in which an accused is administered sedative substances—commonly barbiturates like Sodium Pentothal—to lower inhibitions and suppress conscious control. The underlying assumption is that, in this semi-conscious state, a person is more likely to reveal concealed information.
It is often grouped with so-called “truth serums” and placed alongside polygraph and brain-mapping tests, all of which are considered non-violent but intrusive investigative methods.
Why narco tests clash with Article 20(3)
Article 20(3) of the Constitution guarantees protection against self-incrimination, stating that no person accused of an offence shall be compelled to be a witness against himself. The Supreme Court has consistently interpreted this right broadly, extending it beyond oral testimony to include testimonial responses extracted through scientific or psychological means.
In Selvi, the Court held that involuntary narco tests amount to compelled testimony. Consequently, any information obtained through such means is inadmissible as evidence.
Article 21, privacy, and the “Golden Triangle”
The constitutional problem does not end with Article 20. Forced narco tests also infringe Article 21, which guarantees the right to life and personal liberty, including the right to privacy.
In Maneka Gandhi v. Union of India (1978), the Supreme Court described Articles 14, 19, and 21 as forming the “Golden Triangle” of the Constitution. Any procedure that violates privacy or bodily autonomy, without fairness or consent, fails the test of “procedure established by law” and thus breaches this constitutional core.
Evidentiary value: what courts have clarified
Judicial precedent is clear that narco test results do not establish guilt. In Manoj Kumar Saini v. State of MP (2023) and Vinobhai v. State of Kerala (2025), courts held that such results may at best provide investigative leads but must be corroborated by independent evidence.
The Supreme Court has also laid down strict safeguards:
- Consent must be voluntary and informed.
- Consent must be recorded before a judicial magistrate.
- Medical, legal, and procedural safeguards must be followed.
Even when consent exists, the evidentiary use of the test remains limited.
Consent, autonomy, and natural justice
The Court emphasised that informed consent is rooted in individual autonomy, a core principle of natural justice. A person may volunteer for a narco test at the stage of defence evidence under Section 253 of the Bharatiya Nagarik Suraksha Sanhita (BNSS), but there is no indefeasible right to demand such a test.
Ethically, forced testing undermines human dignity. As philosopher Immanuel Kant argued, an act is ethical only when performed with consent. Compelled narco analysis violates not only constitutional law but also basic moral principles governing state power over individuals.
What to note for Prelims?
- Narco test involves administration of sedatives to extract information.
- Forced narco tests violate Article 20(3) and Article 21.
- “Selvi v. State of Karnataka (2010)” laid down binding guidelines.
- Results of narco tests are not substantive evidence.
- Articles 14, 19, and 21 form the “Golden Triangle” of the Constitution.
What to note for Mains?
- Critically examine the balance between investigative needs and fundamental rights.
- Discuss the scope of Article 20(3) in relation to scientific investigation techniques.
- Analyse the role of consent and privacy under Article 21.
- Evaluate the ethical and constitutional limits of modern criminal investigation methods.
