Nirbhaya Case: Multiple petitions have been filed by the four men to stall their execution.

Hours before they were to hang, the four Nirbhaya case convicts extracted another last-minute reprieve as a Delhi court deferred their execution indefinitely.

Convicts Pawan Gupta, Mukesh Singh, Akshay Singh and Vinay Sharma will not be hanged until further court orders. Their death sentence has already been put off once in a haze of review, curative and mercy petitions.

"The death warrant has been cancelled and no new date has been given," said the lawyer of one of the convicts, AP Singh.

Nirbhaya's mother wept as she said that a convict's lawyer had "challenged" her in court. "He challenged me...he said there would be no hanging," she told reporters after an excruciating day waiting in courts.

Taking advantage of a legal system that the government says is skewed, the convicts filed multiple petitions to stall their hanging.

A new petition was filed today before the Supreme Court and rejected. Pawan Gupta's claim of being a minor at the time of the 2012 gang-rape and killing was dismissed by the Supreme Court for the second time in two weeks. He had asked the court to review its decision last week, even though he had been told that once rejected, an age claim cannot be contested repeatedly.

But it is the mercy petition filed by convict Vinay Sharma that secured today's reprieve. Even if the President rejects it today, the convict has to be given 14 days till execution, under the rules.

Given the pattern, on the 13th day, another convict will file a mercy petition.

On the government's request on January 22 for a change in the rules to prevent convicts from "playing with the law", the Supreme Court today agreed to consider amendments that were more considerate towards the victims and their families. The government has suggested a time limit for the convicts to use their legal options so their death sentence is not delayed endlessly.

The original date of execution was January 22. Because of a mercy petition by Mukesh Singh, a Delhi court set a new date, February 1 (tomorrow) at 6 am. The hangman arrived yesterday at Tihal jail in Delhi, where the convicts were to be hanged together. The law does not allow separate dates of hanging for the same crime.

On December 16, 2012, the young woman who came to be known as "Nirbhaya" was gang-raped by six men on a moving bus, tortured with an iron rod and thrown off the vehicle. She died on December 29.

The savage assault stunned the nation and angry protesters filled the streets in their demand for justice.

Of the six men, one was found hanging in jail. The youngest, just short of 18 when the crime was committed, was released after three years in a reform home.

Nirbhaya's parents say the four men should be hanged tomorrow instead of being allowed to exploit the law to delay the process.

"I have been sitting here (in the court) since 10 am. If the court wanted to spare these criminals again, then why take so long? Why make us sit and hope for so long? We waited all this time, with hope... why not send us home?" she said.