Indian Prime Minister Narendra Modi Photo: Xinhua

Indian Prime Minister Narendra Modi was not complicit in deadly religious riots that broke out in 2002 in one of the bloodiest episodes in independent India, according to a judge-led commission report released on Wednesday.

Modi was the chief minister of the western state of Gujarat when nearly 1,000 people - the majority of them Muslims - were killed in riots triggered by a fire on a train which killed 59 Hindu activists.

The riots have long dogged Modi, who was accused by ­human rights groups of turning a blind eye to the violence.

The Nanavati Commission found that the riots were spontaneous, sparked by the train burning deaths, rather than pre-planned attacks.

"There is no evidence to show that these attacks were either inspired or instigated or abated by any minister of the state," the Nanavati Commission said in its nine-volume ­report of more than 2,500 pages.

The commission also cleared the police force of negligence, finding that police were unable to control mobs as they had inadequate numbers or were not properly armed. 

In 2008, it had concluded that the train incident was a pre-planned conspiracy, with 31 people later convicted of criminal conspiracy and murder by a special court.

More than 100 people have already been convicted over the riots.