The polygraph test on Mehrauli murder accused Aaftab Amin Poonawala went on for nearly three hours on Friday at the Forensic Science Laboratory here, officials said.

The police custody of Poonawala, who allegedly strangled his live-in partner and cut her body into 35 pieces before dumping them, will end on Friday even as the investigation in the case is on.

The police is yet to find the victim's skull and remaining body parts as well as the weapon used to dismember the body.

Poonawala reached the Forensic Science Laboratory (FSL) at Rohini here for his third session of the polygraph test at 4 pm and left after 6:30 pm, they said.

A senior FSL official said all sessions related to the test have been completed, including the pre, main and post stages of the procedure.

"Our forensic experts will analyse the recordings and make a report accordingly. He (Poonawala) can be called again if the experts are not satisfied with the report. Based on the outcome of the report, a decision will be taken on conducting narco analysis which can be carried out even if he is sent to judicial custody," he said.

A series of questions related to the case such as the sequences of events that led to the murder, the accused's relationship with Walkar, reason for their strained relationship, place where he dumped the body parts, type of weapon used, were among some of the questions asked in the test.

The intension was to check for discrepancies in his statement, the official said, adding that the results will be handed over to the investigators within two-three days.

Poonawala had undergone a marathon polygraph test of nearly eight hours on Thursday. However, officials at the facility found it difficult to record his statements as he was not well.

Poonawala allegedly strangled his live-in partner Shraddha Walkar (27) 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 those across the city over several days past midnight.

Meanwhile, the incident has also taken a political turn with Union Home Minister Amit Shah assuring "strict punishment" to the accused in minimal possible time, while the CPI(M) has alleged that the murder and dismemberment of Walker by her Muslim boyfriend was being used for "communal propaganda".