Two days after the incident sent shock waves, police said they were yet get the medical and forensic reports.
"We have been questioning every possible person of the area, including rowdysheeters, the residents and friends of the girl. So far, we have questioned over 80 persons," police said.
The vaginal swab has been sent to the Forensic Science Laboratory (FSL) here for analysis, hospital sources said.
The incident took place on Saturday night in the campus after the gang waylaid the car in which she was going with her boyfriend, an IT employee from Kerala.