The Central Burau of Investigation (CBI) has ruled out gangrape in the death of a 31-year-old Kolkata doctor.
The available evidence indicates only Sanjay Roy - arrested by the police - was involved in the horrific rape and murder at the city's RG Kar Hospital, NDTV reported quoting sources.
Sources said the inquiry is in its "final stages" and that the agency will soon file charges.
Quoting sources, NDTV said the CBI - which has recorded over 100 statements and conducted 10 polygraph tests, including two of ex-hospital chief Dr Sandip Ghosh - has no reason to believe others were involved in raping and murdering the doctor, whose body was found in a hospital room early August 9.
The CBI is expected to file a status report with the Calcutta High Court on September 17.
There have been multiple claims and allegations made, many without substance, alleging conspiracies that led to the doctor's death and claims of her being gangraped. There have also been accusations by her family that police tried to bribe them to cover up the killing, which the cops have firmly denied, NDTV said.
The victim's parents also said this week they had been forced to cremate the body despite wanting to preserve it.
The killing has triggered protests and dharnas across the country, many of which turned violent, including an incident in Kolkata on August 15, Independence Day, in which a mob stormed the campus and allegedly vandalised the seminar room where the body was found.
The Supreme Court, meanwhile, has taken suo moto cognisance of the horrid crime and a hearing is on before a bench led by Chief Justice DY Chandrachud.