‘Intrusion into mental privacy’: How courts treat lie detector tests, amid NEET case plea

The article examines the legal standing of lie detector tests (polygraph, narco-analysis, BEAP) in India, prompted by a NEET paper leak case where accused individuals volunteered for such tests. It highlights the Supreme Court's landmark judgment in Selvi v State of Karnataka (2010), which ruled that compulsory administration of these tests violates the right against self-incrimination (Article 20(3)) and personal liberty (Article 21), intruding upon mental privacy. While voluntary tests are permitted, they require strict safeguards, including consent recorded before a judicial magistrate, access to legal advice, and adherence to NHRC guidelines. Crucially, even voluntary test results are not admissible as substantive evidence of guilt but can be used for corroboration if they lead to the discovery of a physical fact under Section 23 of the Bharatiya Sakshya Adhiniyam. The recent Amlesh Kumar v State of Bihar (2025) judgment further clarified that courts retain discretion in allowing even voluntary requests, especially at early stages of proceedings.