Forensic evidence from the bus in which a 23-year-old New Delhi student was gang-raped links the scene of the crime with men accused of the attack, a public prosecutor in the Indian capital claims.
Feelings still run high in India since the incident three weeks ago, with calls for reforms of laws and policing, and debate continuing on attitudes towards women.
Five men charged with rape and murder have been ordered to appear in court tomorrow. It will be their first public appearance since being detained two days after the attack. They face the death penalty.
Public prosecutor Rajiv Mohan told a judge in the south Delhi suburb of Saket that the men had attempted to destroy evidence by burning their clothes, but that parts of the burned material had been found to have traces of blood from the victim, who died in a Singapore hospital eight days ago.
The men's trial is due to start in a week, in a new fast-track court inaugurated last week specifically to deal with sexual violence against women. The accused, aged between 19 and 35, are being held at Delhi's Tihar prisons. A youth alleged to have taken part in the assault will be tried separately.
The male friend of the victim has described how passersby left the pair lying unclothed and bleeding in the street for almost an hour.
The graphic account in a television interview is likely to add fuel to public anger at the death, in a country where official statistics show that a rape is reported every 20 minutes and where sexual harassment of women in public places is ubiquitous.
The woman's friend told the ZeeNews TV network that he was beaten unconscious before the pair were thrown off a bus they had boarded in the mistaken belief it would take them home after an evening watching the film, Life of Pi, at a nearby shopping centre cinema.
The women was raped for more than an hour and suffered internal injuries after an assault with an iron bar.
The pair lay on the roadside for about 45 minutes before three police vans arrived. Officers then spent a long time arguing about where to take them, the man said. "We kept shouting at the police, 'Please give us some clothes,' but they were busy deciding which police station our case should be registered at," he said. Eventually, the officers fetched a sheet from a nearby hotel. He said they carried the victims to a police vehicle, despite their injuries.
Delhi police spokesman Rajan Bhagat said records showed the first police van reaching the scene four minutes after it was called. He said it left after seven minutes and arrived at a hospital within 24 minutes.
The friend described the pair's attempts to call for help during the attack. "We were shouting, trying to make people hear us. But they switched off the lights of the bus," he said, according to an interview transcript.
When they were finally thrown out at a roadside near the city's airport, they pleaded with passersby for help, he added in the studio interview.
"There were a few people who had gathered round, but nobody helped. My friend was grievously injured and bleeding profusely. We were without clothes. We tried to stop passersby. Several auto-rickshaws, cars and bikes slowed down but none stopped for about 25 minutes. Then, someone called the police."
The man also criticised delays and care at the public hospital where the pair were taken. He said they were again left without clothes or treatment for a long time.
The TV channel that ran the interview is under investigation by police, who claim it has threatened their anonymity.
His revelations will fuel further criticism of authorities in India, who have alternated between promises of reform and a barely disguised contempt for the largely urban middle-class protesters who have taken to the streets over recent weeks.
Underground railway stations in New Delhi have been closed to prevent gatherings in the city centre. Thousands of police were deployed to protect Parliament and senior officials' homes after the news of the attack spread.