A filmmaker behind a new documentary about a fatal gang-rape in India that caused global outrage told Tuesday how one of the men sentenced to death for the killing had shown no remorse during a "chilling" interview.

Mukesh Singh, one of five people convicted over the 2012 attack in New Delhi, told British film-maker Leslee Udwin from his prison cell that the murdered student should not have been out at night, in comments that experts say reflect a wider instinct to blame victims of sex crime.

"What I found when I interviewed him, the most chilling thing that I found, was that I got an insight and understanding into the way he views women and that is what is extremely shocking," Udwin told reporters.

"No regret for one second out of 16 hours (of interviews), no regret. In fact, the opposite. Mukesh's attitude is 'Why are they making a fuss about us, everybody is doing it'," she added in New Delhi before a special screening of the "India's Daughter" documentary.

The 23-year-old physiotherapy student died from her injuries 13 days after she was savagely attacked on a moving bus while on her way home from the cinema with a male friend on December 16, 2012.

Before her death in a Singapore hospital she was able to speak to police about the crime, which caused outrage across the world and triggered mass protests in India.

The attack highlighted the frightening level of violence against women in the world's second most populous country and led to a major reform of the rape laws, speeding up trials and increasing penalties.

But in his interview, Singh said the victim, who cannot be named for legal reasons, should not have been "roam(ing) around at 9 o'clock at night" and that "a girl is far more responsible for rape than a boy".

Udwin said she had read out a list of all the injuries that the victim suffered when she spoke to Singh but he was unmoved.

'Like a robot'

"He is almost like a robot. I tried everything, every trick I knew to try and make him have a tear in his eye or something to see if there was any remorse," she said.

The victim's parents condemned Singh's comments, which caused outrage on television debates.

"What he said is wrong," her father told the NDTV network. "I have taught my children to stand up for themselves, never give up."

The case sparked much soul-searching about India's treatment of women, but campaigners say little has changed in the deeply patriarchal country.

"Indian society is such that it thinks rape is normal, that rape is a part of a woman's fate," sociologist Shiv Visvanathan told AFP.

"Our attitude to rape is as if the victim asks for it and the male is nowhere in sight of blame -- it is the circumstance, the provocation and whole series of symptoms, but men are never blamed," added Visvanathan, who is based in the state of Haryana which has a history of particularly gruesome rapes.

Singh, 28, admitted driving the bus during the incident but denied taking part in the rape. He is appealing the verdict against him.

One of the alleged attackers died in jail before he could be tried, while another was too young to be tried as an adult and is serving a three-year sentence in a reform facility.