The trial court had originally convicted and sentenced 26 people accused of conspiracy to kill Rajiv Gandhi to capital punishment.

In May this year, the Supreme Court confirmed the death sentences of four of the 26. The court commuted the death sentences of three others to life imprisonment and acquitted the 19 other defendants.

'Murder not terrorism'

The four were due to be executed on 9 June but their fate was put on hold after they filed a review petition.

In the petition, the four asked the court to consider the former prime minister's killing as a case of murder and not of terrorism. They said Mr Gandhi's death was the result of personal animosity, which does not warrant a death sentence.

Rajiv Gandhi was killed by a woman suicide bomber while campaigning as leader of the opposition at an election rally in the southern state of Tamil Nadu in May 1991.

Tamil Tigers blamed

The Indian authorities blamed the murder on the separatist Tamil Tigers of Sri Lanka.

Prosecutors said the Tigers had sought revenge on Mr Gandhi because he sent his troops to disarm them under an accord with the Colombo government in 1987.

The prime accused in the case is the Tamil Tiger leader, Velupillai Prabakaran, who is officially recorded as having absconded.