India's Supreme Court has stepped in to prevent the release of three men sentenced to death for their role in the assassination of India's former Prime Minister Rajiv Gandhi in 1991, according to reports.br br The court said the three - Murugan, Santhan and Perarivalan, who were on death row -- cannot be released by the chief minister of Tamil Nadu state, where the attack took place and where they are being held.br br Four others serving life sentences, including Murugan's wife, Nalini, could still go free.