New Delhi, June 11 -- A narco-analysis test cannot be conducted on an accused person without their consent, and the results of such tests cannot form the sole basis of conviction in a criminal case, the Supreme Court ruled on Monday. Emphasising that the pursuit of modern investigative tools cannot override fundamental constitutional protections, the top court underscored that involuntary narco tests infringe upon the right against self-incrimination and personal liberty guaranteed under Articles 20(3) and 21 of the Constitution. A bench of Justices Sanjay Karol and PB Varale set aside a 2023 Patna high court order that had accepted an investigating officer's proposal to conduct narco-analysis tests on all accused and witnesses in a dowry harassment case linked to the disappearance of a woman. "We have no doubt that the impugned order cannot be sustained," said the bench said, adding that "under no circumstances is an involuntary or forced narco-analysis test permissible under law." The court held that the high court erred in accepting the submission of the police for administering the test, noting that it contravened the law laid down in the landmark 2010 ruling in Selvi vs State of Karnataka, where a three-judge bench had declared such techniques unconstitutional if done without consent. "Articles 20 and 21 of the Constitution are non-derogable and sacrosanct rights to which the judiciary cannot carve out exceptions.Involuntary administration of narco-analysis and similar tests is in contravention of the protection given by Article 20(3)...The results of such involuntary tests cannot be considered as material evidence in the eyes of the law," noted the bench. To be sure, a narco-analysis test is a forensic interrogation technique in which a suspect is injected with a psychoactive drug to lower their inhibitions and suppress their reasoning ability, in an attempt to extract information, they might otherwise withhold. The bench further stated that permitting such tests without consent would breach a person's right to privacy and amount to a disproportionate exercise of police powers. The apex court also rejected the state's argument that "modern investigative techniques are the need of the hour," saying such measures must never come at the cost of constitutional guarantees. "While the need for modern investigative techniques may be true, such investigative techniques cannot be conducted at the cost of constitutional guarantees under Articles 20(3) and 21," it said. The Court also clarified that a voluntary narco-analysis test, undertaken at an appropriate stage and with adequate safeguards, may be permissible. However, the outcome of such tests, by itself, cannot form the sole basis for a conviction. "A report of a voluntary narco-analysis test with adequate safeguards in place, or information found as a result thereof, cannot form the sole basis of conviction," held the court....