Anoop Dutt, the ASI, was questioned about his relationship with accused Sanjay Roy and any knowledge he may have of the night of the incident.
CBI sleuths have reportedly accessed multiple photographs showing Dutt and Roy together prompting them to dig out further details on the arrested man from the officer.
Roy, a civic volunteer, who is already in custody, was also interrogated about any interactions he had with the victim among other things.
The agency also plans to question Roy’s relatives in the next few days, it is learnt.
Dr Sandip Ghosh, former principal of RG Kar Medical College, appeared before the CBI for the fifth consecutive day on Tuesday, facing questions about inconsistencies in his previous statements.
The agency also questioned him on why an adjacent portion of the seminar room was demolished and repair work started during the investigation. Allegations of dereliction of duty and attempts to cover up the incident have been levelled against Dr Ghosh.
Meanwhile, two assistant commissioners of police and an inspector have been suspended in connection with the vandalism at the hospital on August 14. Assistant commissioners Shakir Uddin Sardar, Ramesh Shah Chowdhury, and inspector Rakesh Minz have been accused of negligence as they were on duty at the hospital that night. A departmental inquiry has been initiated into them.
So far, the police have arrested 37 people in connection with the mob attack and vandalism at the hospital.
Click here to join The Indian Express on WhatsApp and get latest news and updates