Kolkata/IBNS: Civic volunteer Sanjoy Roy, who has been arrested in connection with the rape and murder of a 31-year-old trainee doctor at Kolkata's RG Kar Medical College and Hospital, was spotted at the crime scene on CCTV, media reports said.

Sanjoy was spotted with a Bluetooth earphone suspended from his neck.

The investigators have released the footage from the crime scene.

The Bluetooth headphone had served as a clue for the Kolkata Police, which had arrested Sanjoy, who had admitted to the crime.

Sanjoy reportedly visited Sonagachi (red light area) and then visited two brothels and drank alcohol before committing the crime.

He then reached the hospital at 1:03 am on the night the medical student was raped and murdered.

Sanjoy was also spotted leaving the seminar room where the crime was committed.

The Central Bureau of Investigation (CBI), which is now probing the case under the monitoring of the Supreme Court, has already received permission to conduct a polygraph test on RG Kar Hospital's former Principal Sandip Ghosh and four other doctors.

The CBI has found fingerprints of two of these four doctors in the third-floor seminar room where the body was found.

A CCTV camera had captured the house surgeon going from the first floor to the third floor that night.

The house surgeon has said he went to the third floor at 2.45 am that night. The intern was on the third floor and had spoken to the victim that night, the CBI has reportedly found.