This Supreme Court ruling arose from a missing person case where Amlesh Kumar was accused of dowry harassment and suspected in his wife’s disappearance. The key issue was whether a High Court could accept a police proposal for narco-analysis tests on the accused during bail proceedings. The Supreme Court held that involuntary narco-analysis tests violate Articles 20(3) and 21 of the Constitution, infringing the right against self-incrimination and personal liberty. Even if taken voluntarily, such tests have limited evidentiary value they cannot be the sole basis for conviction and can only support material evidence under Section 27 of the Evidence Act. Moreover, accused persons have no absolute right to demand such tests; the Court must examine consent, stage of trial, and whether appropriate safeguards under the Selvi v. State of Karnataka guidelines have been met. The Supreme Court set aside the Patna High Court’s order allowing such tests at the bail stage, reinforcing these legal protections and procedural requirements.