The Justice Project Pakistan (JPP), a human rights law firm representing Shafqat Hussain, said the Supreme Court in the capital Islamabad had agreed to hear its appeal against an earlier court decision that rejected an inquiry into the case.
The Supreme Court adjourned the hearing until today.
His brother Manzoor Hussain said relatives gathered in Muzaffarabad, the main town of Pakistani Kashmir, to keep a vigil during the night of the expected hanging.
“When we were informed at 3am that he has survived, we felt a wave of life inside us,” he told AFP. “We were not expecting this, we had even found a place for his grave in a local cemetery here in Muzaffarabad.”
In a separate case, another death row inmate, who activists say was convicted when he was a minor, is due to be hanged today in the city of Lahore.
Aftab Bahadur was sentenced to death for murder in 1992, but human rights group Reprieve said the two witnesses who implicated him have since recanted, saying they were tortured.
In a letter from jail, Bahadur repeated his assertion that he was innocent and was 15 years old in 1992.
His lawyers have provided documents which they say disprove prosecutors’ assertions he was 21.
“I have served this dreadful life sentence already, and yet they want me to suffer another punishment on Wednesday — death by hanging,” he wrote of more than 22 years behind bars.
The JPP filed separate appeals to President Mamnoon Hussain urging clemency for both men.
They are among more than 8,000 people on death row in Pakistan, according to Reprieve, the largest number of any country.
Reprieve estimates 150 people have been executed in Pakistan since mid-December, when prime minister Nawaz Sharif lifted a moratorium on the death penalty.
His decision came a day after Taliban militants attacked a school killing more than 130 pupils and 19 adults.
The stay for Hussain was the fourth in six months, and came just hours before he was due to be hanged.
A JPP spokesman said that on this occasion, Hussain would have been changed into white clothes and moved to a different part of the prison in preparation for his execution.
“Each time he has to say goodbye to his brothers. He has to go through this over and over again,” the spokesman said.
Hussain’s lawyers say he was 14 in 2004 when he was burnt with cigarettes and had fingernails removed until he confessed to killing a child. Authorities say he was 23 when he was sentenced.