Pictured: The shamed faces of the Indian bus rapists as they are led into court to appeal 'the sword of death hanging over them'

Akshay Thakur, Pawan Gupta, Vinay Sharma and Mukesh Singh are appealing against their death sentences

They were sentenced to death by hanging for gang raping and torturing a 23-year-old student on a bus in December last year

It could take months for the court to hear review evidence and consider the appeals before deciding whether to confirm the execution orders

Lawyers for four men sentenced to death for raping and murdering a young woman on a New Delhi bus challenged the convictions and death sentences at a High Court hearing today.



The brutal attack in December sparked public debate and fury over chronic sexual violence faced by women in India.



A P Singh, who has defended all four men at various times confirmed: ' I am challenging this verdict.'

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Arriving at court: Akshay Thakur, center left, and Pawan Gupta, center right, two of the four men sentenced to death for the notorious Deli bus rape get down from a police van as they are brought to High Court in New Delhi, India

Indian police officials escort Vinay Sharma to the High Court as he tries to appeal against his death sentence for the fatal gang rape of a student

Lengthy process: The High court is holding daily hearings but it could be weeks before the decide whether to confirm the death sentence handed to the four men on September 13

The High Court in New Delhi said it would begin hearing prosecution arguments tomorrow, while defence solicitors file their appeals against the convictions and sentences.



Judge Pratibha Rani said: ' We have to deal with this as expeditiously as possible because the sword of death is hanging over them.'

It could take weeks or months for the court to hear arguments, review evidence and consider the appeals before deciding whether to confirm the execution orders.



A review is required for all death penalty cases in India, and the same court is hearing the men's appeals.

Sentence to death: Two of the men - Mukesh Singh, left and Vinay Sharma right - who have been sentenced to death by hanging for attacking a 23-year-old student in Delhi

Akshay Thakur, centre left, and Pawan Gupta and centre right, don't believe they should be executed for their part in the gang rape and torture of 23-year-old student last year

Indian police officials escort Mukesh Singh, left, and Akshay Thakur, right, into court, the force of public anger over the case has required a huge police presence each time the men have been out in public

Rapists: Mukesh Singh, left, and Akshay Thakur, right,

Guilty: Vinay Sharma, left, and Pawan Gupta, right, face death by hanging if their appeal is not successful

For today's hearing, the men walked under police escort from a bus into the High Court complex.



In sentencing the four, trial court Judge Yogesh Khanna said the crime had 'shocked the collective conscience' of India.



The four had been joyriding through New Delhi on a bus on the night of December 16 when they lured the 23-year-old woman and her male friend into boarding.

They then beat the friend and took turns raping the woman and abusing her.



She died from internal injuries two weeks later.



Another defendant hanged himself in prison, though his family insists he was killed.



And an 18-year-old who was a juvenile at the time of the attack was sentenced in August to a maximum of three years in a reform home.



Shocking details: During the trial horrifying details of the attack were read to the court which only further enraged the crowds clamouring for the deaths sentence