The supreme court today blocked the release of former prime minister Rajiv Gandhi’s killers, saying the Tamil Nadu government had no power to remit their sentences without the centre’s consent.

Upholding life sentences for all seven convicts in the case, the court said the state government couldn’t release them as the Centre had the final say in cases where the probe was carried out by a central agency such as the CBI.

On February 18 last year, the court had commuted the sentences of AG Perarivalan alias Arivu, Sriharan alias Murugan and T Suthentiraraja alias Santhan, who were the only ones facing the death penalty in the case at the time, citing inordinate delay in their executions. Four others were already serving life terms.

A day later, Tamil Nadu announced the release of the convicts, triggering widespread celebrations in the state with support from all political parties, except the Congress.

A five-judge constitution bench headed by chief justice HL Dattu was hearing a petition by the central government challenging the order. It was assumed that the release order was issued to cash in on pro-Tamil sentiments for the Lok Sabha polls.

The former PM was killed by a suicide bomber from the LTTE while campaigning in an election in Tamil Nadu’s Sriperumbudur city in 1991 after he dispatched Indian troops to aid Sri Lanka in its fight against the separatist militant group.

A total of 26 people were found guilty of conspiring to kill Rajiv Gandhi, but 19 of them were later acquitted amid a wave of sympathy for the killers, who were seen to have been fighting for the Tamil cause in Sri Lanka.