Explainer | What is a narco test, which will now be administered to Aftab Amin Poonawala?

However, statements made during narco analysis test are not admissible in the court, except under certain circumstances when the court thinks that the facts and nature of the case permit it.

A Delhi Court ordering a narco test for Aftab Amin Poonawala in the bone-chilling Shradha Walkar killing case has put the spotlight on use of the specialised examination as an advanced tool for interrogation.

Also known as truth serum, it has been used for solving crucial cases in the past.

The test involves the intravenous administration of a drug (such as sodium pentothal, scopolamine and sodium amytal) that causes the person undergoing it to enter into various stages of anaesthesia.

In the hypnotic stage, the person becomes less inhibited and is more likely to divulge information, which would usually not be revealed in the conscious state.

The investigating agencies use this test after other evidences do not provide a clear picture of the case.

According to norms, the consent of the person is also necessary for being subjected to narco test.

The Supreme Court had ruled that narco analysis, brain mapping and polygraph tests cannot be conducted on any person without his or her consent. The apex court had noted in response to petitions questioning the validity of such tests, are illegal and a violation of personal liberty.