The male friend of the Indian gang rape victim has spoken for the first time of how he tried to save her and begged her attackers to stop the "cruelty that should never be seen".
He broke his silence as New Delhi district magistrate Namrita Aggarwal confirmed that the five men charged with the victim's rape and murder will appear before her for the first time on Monday.
The victim's 28-year-old male companion said getting on to a private bus that night, because they could not find a rickshaw to take them home, was "the biggest mistake I made".
Speaking in public for the first time, he hit out at the hospital treatment his 23-year-old friend received, the police and passers-by for failing to help after they were thrown naked from the bus following the two-and-a-half-hour ordeal.
The software firm employee said that the woman was left naked and bleeding in the street for nearly an hour before a police van arrived to help.
"What can I say? The cruelty I saw should not be seen ever. I tried to fight against the men but later I begged them again and again to leave her," he told AFP.
"I was not very confident about getting into the bus but my friend was running late, so we got into it.
"This was the biggest mistake I made and after that everything went out of control.
"The driver and the other men raped my friend and hit her in the worst possible ways in the most private parts of her body.
"I cannot tell you what I feel when I think of it. I shiver in pain," he said.
The man, who suffered a fractured leg and other injuries in the attack, recounted the savagery of the night of December 16 after he and his friend, who died from her injuries on December 29, had been to see a film in New Delhi.
He told the Hindi-language cable channel Zee News : "The occupants of the bus, which had tinted windows and curtains, had laid a trap for us. They were probably involved in crimes before also. They beat us up, hit us with an iron rod, snatched our clothes and belongings and threw us off the bus on a deserted stretch.
"The bus occupants had everything planned. Apart from the driver and the helper, others behaved like they were passengers. We even paid 20 (rupees) as fare. They then started teasing my friend and it led to a brawl. I beat three of them up but then the rest of them brought an iron rod and hit me. Before I fell unconscious, they took my friend away."
"From where we boarded the bus, they moved around for nearly two and a half hours. We were shouting, trying to make people hear us. But they switched off the lights of the bus. We tried to resist them. Even my friend fought with them, she tried to save me. She tried to dial the police control room number 100, but the accused snatched her mobile away."
The attackers also violated the victim with an iron bar, causing the immense internal damage that led to her death, before throwing them from the bus.
The friend said: "There were a few people who had gathered round but nobody helped. Before the police came I screamed for help but the auto rickshaws, cars and others passing by did not stop."
He said when police arrived: "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."
"It took an hour and a half for us to be taken to hospital."
The police have arrested six suspects - five men and a juvenile believed to be aged 17 - who were formally charged with murder, rape and kidnapping on Thursday.
The case has sparked massive protests across India, where statistics show a woman is raped every 20 minutes.
Protesters have called for all rape suspects to be hanged and want a better deal for women so the streets are safer and men who rape women are put on trial.
National crime records show that 228,650 of the total 256,329 violent crimes recorded in India last year were against women and rape cases more than doubled between 1990 and 2008.
Police in Delhi have filed charges against Zee News under laws which protect the anonymity of victims of offences such as rape. In India, the criminal justice system defines rape as a crime against the state, and says it is the responsibility of the state to defend the victim.