It has been reported that the central probe agency has filed an FIR under various sections of the Bharatiya Nyaya Sanhita (BNS) in New Delhi in connection with the alleged rape and murder of the doctor.

On Thursday morning, the probe team including the special crime unit of the agency and also its local unit initiated the investigation after reaching Kolkata.

CBI investigates RG Kar incident: Top points

• CBI took possession of all the documents from Kolkata Police on the probe done by it so far, the officials said.

• The investigating team also includes a joint director besides medical and forensic experts, and officers having extensive experience in special crime cases

• The team visited the RG Kar Medical College and Hospital's seminar hall, where the body of the trainee doctor was found on August 9, they said.

• Kolkata Police today handed over key suspect Sanjoy Roy to the CBI at the CGO Complex after his medical tests were conducted at the state-run SSKM Hospital.

• It has been reported that the investigating CBI team would camp in Kolkata till the case is solved

• Three groups of CBI officers have been formed to investigate the matter, an official of the central agency said.

• CBI officers today also visited the residence of the doctor who was raped and murdered at a Kolkata hospital, and spoke to her parents.

• The investigators took note of the time they received the call from the hospital, informing them about the death of their daughter, he said.

• Moreover, CBI also reached out to five doctors of the hospital, its former medical superintendent-cum-vice-principal (MSVP), principal and the head of the Chest Department where the victim's body was found.

• The investigators have sought details of Civic Volunteer Sanjay Roy's call detail record and mobile tower location, among others. He was arrested after the victim's body was found on Friday.