A is arrested by police and accused of murder of B. During investigation A voluntarily agrees to…

A confession made during narco-analysis is not admissible as substantive evidence even if the accused consented to the test, and a confession to the police is in any case barred by sections 25 and 26 of the Indian Evidence Act. In Selvi v. State of Karnataka (2010) the Supreme Court held that information or material subsequently discovered with the help of a voluntarily administered test can be admitted under section 27. So "Only that much of A's statement can be used as leads to discovery of a fact"; the confession can be neither the sole basis of conviction nor used as a corroborated confession.

Current law: BSA section 23 retains the police-confession prohibition and the discovery proviso. In Amlesh Kumar (2025), the Supreme Court reaffirmed that courts cannot compel narcoanalysis or use it as a bail condition; even voluntary test results are not themselves admissible, while derivative discovery remains governed by law.