BBC documentary on 2012 Delhi gang-rape outrages India

Members of All India Mahila Congress, women's wing of Congress party, shout slogans and carry placards during a protest against the rape of a female passenger, in New Delhi, December 8, 2014. [Photo/Agencies]

Another expert, Prof. Ajay Singh, said: "In cases like rapes, the judiciary has to ensure that justice is delivered fast and not delayed. Even a fast-track court took seven months to give its judgment and the case has been lying in the Supreme Court for the last year."

The filmmaker has meanwhile said that she sought and got permission from the Indian Home Ministry to conduct the interview of one of the rapists. "I had applied for permission in May 2013 and I got the answer yes in two weeks," she told the media in the national capital.

Udwin has also defended her documentary during a discussion at a TV studio, saying it "tries to show the disease is not the rapists, the disease is in society."

The BBC has also defended the documentary.

"This harrowing documentary, made with the full support and cooperation of the victim's parents, provides a revealing insight into a horrific crime that sent shock waves around the world and led to protests across India demanding changes in attitudes towards women," a spokesperson said.