A teenager in India has been sentenced to three years in juvenile detention by a court in New Delhi for the gang rape of a trainee physiotherapist last December.

It is the first verdict in a case that sparked debate over whether India is too soft on young offenders.

According to police, the 18-year-old and five other men lured the 23-year-old woman and her male friend onto a New Delhi bus where they repeatedly raped her and beat them both with a metal bar before dumping them on to a road.

The woman died in a Singapore hospital two weeks after the attack.

The case turned a global spotlight on the treatment of women in India, where police say a rape is reported every 20 minutes.

The court found the juvenile guilty under rape and murder charges, and accordingly sentenced him to three years in jail.

A lawyer for the accused said the juvenile would be sent to a reform home to serve the term, taking into account the months he has already spent in detention since his arrest.

Four of the teenager's co-accused are still on trial and face the death penalty if convicted.

Closing arguments began on 22 August and verdicts are expected within the next fortnight.

A fifth accused, the alleged ring-leader, killed himself in his jail cell in March.

The teenager, who cannot be named, was tried as a juvenile as he was 17 at the time of the attack.

The maximum penalty that could be imposed by the Juvenile Justice Board was three years.

In January, authorities ruled he was 17, citing school records, which shocked the victim's family and others wanting him to face the death penalty.

The family of the victim was distraught after hearing the verdict the mother of the young girl said that this judgment would make other girls in the country more vulnerable to such brutalities.

“We want him to be hanged and we will challenge this verdict in the High Court. I am not at all happy with this verdict. By not punishing this teenager, this verdict is encouraging other teenagers to indulge in such acts and does not provide any safety to girls”, she said.

The teenager pleaded not guilty to all 13 charges including rape, murder and robbery. His trial was held behind closed doors to protect his identity and media were barred from reporting on any details of the proceedings.

During his trial, he has been held at a juvenile detention facility for violent young offenders in Delhi and kept away from other inmates for his safety.

The youth left home when he was 11 and worked in a roadside eatery, his mother told Reuters in January.

In recent years he lived as a semi-vagrant, washing buses and collecting fares, according to a police report.

After he left his home, he never returned back. His mother said she thought he was dead until police arrested him in connection with the gang rape.

In response to the public outcry after the rape, the government fast-tracked tougher laws against sex crimes, but it resisted calls to change the juvenile law and return the adult age to 16 from 18.

The Supreme Court is currently hearing a petition filed by Subramanian Swamy, an opposition politician and lawyer that calls for the law to be reinterpreted rather than changed.