India's Supreme Court has told the government in the state of Gujarat to appoint new public prosecutors to probe last year's religious violence.
The riots left between 1,000 and 2,000 dead - mostly Muslims
And the court says the new appointees must be vetted by the federal government's top lawyers.
Last month the court said it had "no faith left" in the Gujarat government's handling of the cases.
Official figures said more than 1,000 people, most of them Muslims, died in the riots.
Other estimates put the death toll at around 2,000.
Criticism over trial collapse
Analysts say Thursday's Supreme Court decision is a further blow to Gujarat's Hindu nationalist government which appoints the lawyers to try those accused of rioting last year.
The court said the new prosecutors appointed must be approved by the highest judicial officer in the country - the attorney general.
Zaheera Sheikh is demanding a retrial
It has also appointed Harish Salve, a former solicitor general, to sit in on the riot trials as a special adviser to the court.
The BBC's Jyotsna Singh in Delhi says Mr Salve's appointment is seen as significant as he has a reputation for being tough and independent-minded in public interest cases.
The Supreme Court released its decisions while hearing a petition from India's National Human Rights Commission and a teenage Muslim woman, Zaheera Sheikh.
They are asking the court to order a retrial following the controversial acquittal of 21 Hindus last June in what has become known as the Best Bakery case.
Twelve Muslims, including Ms Sheikh's father, died when a Hindu mob burned down a bakery during the riots.
Ms Sheikh was one of a number of witnesses whose decisions not to testify led to the collapse of the case.
She later said that she had been intimidated.
Ms Sheikh now lives outside Gujarat.
In a separate development, the Gujarat Government said on Thursday that it wanted the Gujarat high court to reopen the Best Bakery case.
The Gujarat riots were triggered after a mob, thought to have been Muslim, torched a train carrying Hindus from Ayodhya, a north Indian town where a campaign is being waged for a temple to be built on the site of a demolished mosque.
Fifty-nine Hindus died in the train attack.