Narco test on Aftab Poonawala, accused of murdering his live-in partner Shraddha Walkar, is likely to be conducted on Thursday, sources said.
The 28-year-old will, however, have to undergo a set of tests to ascertain his emotional, mental, physiological and psychological well-being. The narco analysis cannot be conducted if he is found to be "disturbed" in the preliminary tests.
On Tuesday, Poonawala had undergone a polygraph test, also known as a lie detector test, at the Forensic Science Laboratory (FSL), with police hoping to find vital clues in the murder.
The narco analysis involves administering the individual medication which reduces their self-consciousness and allows them to speak freely.
The polygraph test, on the other hand, records physiological phenomena such as blood pressure, pulse rate and respiration, and the data is used to determine whether the person is speaking the truth.
Poonawala allegedly strangled Walkar and sawed her body into 35 pieces which he kept in a 300-litre fridge for almost three weeks at his residence in South Delhi's Mehrauli before dumping them across the city over several days past midnight. The murder occurred in May.