The remaining sessions of the polygraph test on Aaftab Amin Poonawala, accused of brutally killing his live-in partner Shraddha Walkar, got underway at the Forensic Science Laboratory (FSL) in Rohini on Monday, officials said.

Poonawala reached FSL at 9.50 am and the sessions began at around 11 am, they said.

"When the last session was held, there was a health issue due to which some sessions were not satisfactory. Our lab and preparation for the narco test is complete," Head of the Department of Crime Scene Management at FSL, Rohini, Sanjeev Gupta, said.

"Whether Aftab is cooperating during the test or not, we will tell the investigating agency as this is a confidential matter," he said.

Poonawala has already undergone three sessions of the test, also known as lie-detector test, the last being held for about three hours on Friday.

Tihar jail PRO Dheeraj Mathur said Poonawala is in Tihar jail number 4. When he came, his health check-up was done and there were no issues, he said.

He has been kept in a separate cell and is under 24-hour CCTV monitoring.

"The jail superintendent has received an order from the court that Poonawala should be presented before the Director of FSL Rohini on November 28, 29 and December 5. The third Battalion of Delhi Police will present him before the FSL Director," Mathur said.

Poonawala allegedly strangled Walkar (27), and sawed her body into 35 pieces, which he kept in a 300-litre fridge for almost three weeks at his Mehrauli residence in South Delhi, before dumping them across the city over several days.

He was arrested on November 12 and sent to five-day police custody, which was further extended by five days on November 17.

On November 22, he was sent to four more days of police custody. On November 26, the court sent him to judicial custody for 13 days.

The police are yet to find Walkar's skull and some other body parts as well as the weapon used to dismember her body.

Earlier, the Delhi Police, along with teams from the Municipal Corporation of Delhi, pumped out water from a pond at Maidan Garhi in Chhatarpur area after Poonawala claimed that he had thrown Walkar's severed head and some other remains there.

They had seized five knives from Poonawala's flat and sent them to FSL to ascertain if they were used in the crime.