Four nurses, who were posted at the nursing station of RG Kar Medical College and Hospital on the night of August 8 when the postgraduate trainee was raped and murdered, were questioned at the CBI office in the CGO Complex, Salt Lake, on Thursday.

Sources in the CBI said according to the statement of the parents of the slain doctor, one of the nurses, named Sampa Das, had reportedly recorded video footage of the night of the crime.

Das was one of the nurses questioned on Thursday.

The central agency summoned seven nurses, four of whom went to the CGO Complex on Thursday. The other three are likely to turn up for interrogation on Friday, the CBI sources said.

Last August, an on-duty 31-year-old postgraduate trainee was found raped and murdered in the seminar hall on the third floor of the hospital’s emergency building. A nursing station is located on the same floor. The seven nurses summoned by the CBI were on duty at the nursing station on the night of the crime.

The sources said the nurses were asked about the night in detail on Thursday.

Although one man — Sanjay Roy — had been sentenced to life in connection with the rape and murder of the doctor, her parents have been saying the central agency should expand their scope of investigation and include others who could be involved in the crime. The bereaved parents made multiple petitions — before Calcutta High Court and the Supreme Court of India — on the same grounds.

The Supreme Court recently allowed the parents of the doctor to pursue the case with Calcutta High Court.

The parents had also gone to the CBI headquarters in Delhi and met the agency’s director to make an appeal to extend the scope of the investigation.

The CBI has not yet submitted their supplementary chargesheet in the case.

Last year, the agency arrested former RG Kar principal Sandip Ghosh and the
then officer-in-charge of Tala police station Abhijit Mandal. However, as the CBI did
not submit chargesheets against them within 90 days of their arrest, they were granted bail.

Sources in the CBI said they wanted to add more witnesses to the case and examine more people, which would help them file the supplementary chargesheet.