Those questioned by the central agency belong to different departments of the hospital. The CBI team also met the victim’s family members and recorded their statements.

The agency also summoned Abhijit Mondal, officer-in-charge of Tala Police Station where a case of unnatural death was lodged first after the crime came to the fore. Mondal handed over some documents related to the case to the central agency. Four PGT students of the medical college also recorded their statements, it is learnt.

“I was called and cooperated with the agency. I replied to all questions,” said a Forensic Medicine department faculty member, requesting anonymity.

The CBI investigation, ordered by the Calcutta High Court, is focusing on the accused’s movements on the night of the crime. The CBI is examining the accused’s phone records and tower location data. The agency is also going through his messages and call logs as part of the investigation, sources said.

CCTV camera footage has revealed that the accused entered the hospital around 11pm and left after some time only to return early in the morning. He can be seen going towards the seminar hall where the doctor’s body was found, it is learnt.

The body of the doctor was recovered from the fourth-floor seminar hall on Friday. Police had arrested the key suspect within six hours of the incident, but the agency is looking into the possibility of involvement of more than one person.

Click here to join The Indian Express on WhatsApp and get latest news and updates