India's Supreme Court has upheld the death sentences of four men convicted of the gang rape and murder of a student in Delhi.

Akshay Thakur, Vinay Sharma, Pawan Gupta and Mukesh were given the death penalty by a court in 2013, reports the BBC.

Rejecting their appeal, Justice R Banumathi said the men committed “a barbaric crime” that had “shaken society's conscience”.

The brutal gang rape led to nationwide outrage and and new anti-rape laws.

The 23-year-old physiotherapy student was attacked on a bus that she had boarded with her male friend as they returned home from watching a film in December 2012. Her friend was also beaten up.

Jyoti Singh - whose name was publicly revealed by her mother only in 2015 - died from injuries in a hospital 13 days later.

Media reports said relatives of Ms Singh applauded as the judgment was read out in court.

“This is a historic message to all the people, the criminal mindset who wrong women, who inflict violence on women, to know that if you do something like this you will be also paying for it by the severest punishment that exists in our laws of the land,” Ranjana Kumari, a women's rights activist. 

Legal experts say it could still be months or even years before the sentences are carried out.

The four men still have the right to file a review petition in the Supreme Court. Their last hope lies with a plea for clemency to the president.

Six men were arrested over the attack on Ms Singh. One suspect, Ram Singh, was found dead in jail in March 2013, having apparently taken his own life.

Another, who was aged 17 at the time, was released in 2015 after serving three years in a reform facility - the maximum term possible for a juvenile in India.

Convicting the four men in 2013, Judge Yogesh Khanna said the case fell into the “rarest of rare category” which justifies capital punishment in India.

BDST: 1805 HRS, MAR 5, 2017
AP