The investigation into the rape and murder of a postgraduate doctor at Kolkata's RG Kar Medical College has intensified, with the Central Bureau of Investigation (CBI) conducting polygraph tests on the accused, Sanjay Roy, and other individuals connected to the case. Roy, who initially confessed to the crime, later claimed innocence during his polygraph test, which flagged several of his answers as false or unconvincing. The CBI is also probing alleged financial irregularities within the institution, with former principal Sandip Ghosh and ex-medical superintendent Sanjay Vashisth being questioned for issuing illegal tenders and other corrupt practices. The victim was raped and killed on August 9, leading to nationwide protests. The CBI's findings and the results of the polygraph tests will guide further investigative actions.