India's top human rights watchdog has called on the Indian Supreme Court to order a retrial of 21 Hindus acquitted of murdering 12 Muslims in religious riots in the western state of Gujarat last year.
The riots left between 1,000 and 2,000 dead - mostly Muslims
The men were cleared by a lower court on 27 June after dozens of witnesses retracted statements they had given to police identifying the attackers.
The Hindus were accused of burning the Muslims to death after setting fire to a bakery in Vadodara, 100 kilometres (60 miles) south of Ahmedabad, Gujarat's largest city.
A key witness - the daughter of the bakery owner - has since come forward, saying she had been too afraid to tell the truth when she appeared at the trial.
It was the first trial connected to the violence, in which more than 1,000 people - mostly Muslims - died in three months of rioting.
The witness, 19-year-old Muslim Zaheera Sheikh, said she lied in court following death threats from members of the ruling Hindu nationalist BJP Party in Gujarat.
In a statement, the Indian National Human Rights Commission said it was "deeply concerned about the damage to the credibility of the criminal justice system".
"Violation of a right to fair trial is not only a violation of fundamental right under our constitution but also violative of the internationally recognised human rights," it said.
The Supreme Court is expected to respond in the next few days.
The attack on the Best Bakery on 1 March, 2002, was one of the bloodiest incidents of communal violence in India in a decade.
The riots were sparked two days earlier when a train carrying Hindu pilgrims was torched, killing nearly 60 people.