The decision of the state government to release the convicts was challenged by the Centre before the Supreme Court which had stayed the decision and referred the matter to a Constitution Bench.
The court had on February 20 stayed the decision to release of three convicts--Murugan, Santhan and Arivu-- whose death sentence was commuted to life term by it on February 18 in the case, saying there had been procedural lapses on the part of the state government on the decision to release them.
The apex court later on had also stayed release of convicts Nalini, Robert Pious, Jayakumar and Ravichandran in the case.
Santhan, Murugan and Arivu are currently lodged in the Central Prison, Vellore and they are in jail since 1991.
The other four are also undergoing life sentence for their role in Rajiv Gandhi's assassination on May 21, 1991 in Sriperumbudur.