Narco, lie detection tests illegal: SC

New Delhi: The Supreme Court on Wednesday declared as "illegal" use of narco-analysis, brain-mapping and polygraph tests -- important tools in police investigative process-- on suspects.

"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," said a bench headed by Chief Justice K G Balakrishnan and comprising Justices R V Raveendran and Dalveer Bhandari.

The court said that involuntarily subjecting a person -- an accused, a suspect or a witness-- to such techniques violates the Constitution’s Article 20 (3), which prohibits self-incrimination.

Forcing an individual to such methods of investigation violates the scheme of legal process. Even if people are subjected to such investigations with their consent, the result of the test cannot be an admissible piece of evidence.

However, the court said if anything obtained by the investigators from such techniques in which a person had volunteered, the agencies can use them for further probe.

Several petitions had challenged the constitutional validity of narco-analysis test, which is an important part of police investigation and was used in several high profile cases like the mult-crore Telgi stamp paper scam.

The petitions said narco-analysis conducted on an accused, without his consent, was illegal and should not be admissible as evidence before a trial court as the law prohibits forcing an accused to give evidence against himself.

Former Delhi Police commissioner Ved Marwah said the judgment is not a setback for investigating agencies. He described as narco-analysis tests “as a fall back in blind cases”.

Senior lawyer K T S Tulsi, who is the counsel for victims of the 1984 anti-Sikh riots, welcomed the Supreme Court verdict said the scientific and constitutional validity of the tests was always under question.

(With inputs from PTI and CNN-IBN Correspondents. )

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