In a blow to investigating agencies, the Supreme Court on Wednesday declared as "illegal" compulsory use of narco-analysis, brain-mapping and polygraph tests on suspects.
It, however, held that if anything is obtained by the investigators from such techniques in which a person had volunteered, the agencies can use that for further probe.
"We are of the considered opinion that no individual can be forced and subjected to such techniques involuntarily, and by doing so it amounts to unwarranted intrusion of personal liberty," a bench headed by Chief Justice K G Balakrishnan said.
The apex court said that involuntarily subjecting an accused, a suspect or a witness to such techniques violates Article 20 (3) of the Constitution, which prohibits self- incrimination.
The judgement assumes significance as probe agencies have used narco-analysis, brain-mapping and polygraph tests in a number of high-profile cases involving fake stamp paper kingpin Abdul Karim Telgi, Nithari killings accused and Aarushi murder case suspects as well as parents of the teenager.
The bench, also comprising Justices R V Raveendran and Dalveer Bhandari, observed that forcing an individual to such methods of investigation violates the scheme of legal process.
Even if a person is subjected to such a mode of investigation on consent, the result of the test cannot be an admissible piece of evidence, it said.
The Supreme Court had on January 25, 2008 reserved its order on a batch of petitions challenging investigation techniques like brain mapping, lie detection and narco- analysis as being illegal and unconstitutional, especially in cases where accused were opposed to them.
Those who had moved the apex court included Santokben Sharmanbhai Jadeja, a woman accused of leading an underworld gang in Gujarat, Tamil Film producer K Venkateswara Rao, fake stamp paper scam accused Dilip Kamath and independent Maharashtra MLA Anil Gote.
The Centre had favoured use of technology in the criminal investigation before the Court maintaining that narco-analysis, brain mapping and polygraph tests are integral tools of probe which were legal and valid.
The Delhi High Court had also recently restrained police from going ahead with narco-analysis test on top Maoist leader Kobad Ghandy in view of the pendency of the legality of such tests in the apex court.
The Supreme Court bench said subjecting a person to such techniques amounts to intrusion of personal liberty under Article 21 of the Constitution.
The court further observed that in conducting the polygraph test, the investigating agencies have to follow strictly the guidelines laid down by the National Human Rights Commission (NHRC).
During the hearing on the matter, the Centre had submitted that these tests provided some clues to the investigating agencies and did not have any evidentiary value per se.
Even Law Commission was of the opinion that such a provision was necessary for effective investigation and it would not affect the fundamental rights, it had said, adding "no invasive procedure is involved" in using modes of investigation like lie detector and the brain mapping tests.
It had argued that the use of narco analysis was of particular relevance in the context of terrorist-related cases, conspiracy to commit murder and other serious offences in which probe agencies got vital leads for follow up action.
On May 3, a Rajasthan court had granted the state's Anti- Terrorism Squad permission to conduct narco-test on Devendra Gupta, an accused in the 2007 Ajmer Dargah blast case. PTI
