“We will continue our fight, and won’t let investigations stop… Come what may, we will fight for justice,” the woman’s father told AFP news agency.

Indian law prohibits revealing the identity of victims of sexual violence and that of their family members.

The trainee doctor’s murder at the hospital in the eastern city of Kolkata where she worked sent shockwaves across the country last August.

The 31-year-old had gone to sleep in the seminar hall of the state-run RG Kar Medical College and Hospital after a night shift. Her half-naked, severely injured body was later discovered near a podium by a colleague.

The crime sparked widespread protests and concerns over the safety of healthcare workers in India, especially women.

According to the chargesheet filed by the Central Bureau of Investigation (CBI), which the BBC has seen, Roy went to the hospital in a drunken state and found the female doctor sleeping alone.

The autopsy report indicated that the woman had been strangled and had injury marks that showed she fought back.

Roy was arrested a day after the crime and has consistently denied the allegations.

In Kolkata, doctors went on strike for weeks, demanding action against the accused and officials who they said were complicit in delaying or derailing the investigation.