Hanging of four aides of sandalwood smuggler Veerappan has been further delayed with the Supreme Court on Wednesday extending its interim order staying the execution of death sentence imposed on them for killing 22 police personnel in a landmine blast in Karnataka in 1993.

A bench headed by Chief Justice of India Altamas Kabir said it was keeping the matter pending since another bench, which has heard an identical plea, has reserved its judgement.

"In our view, the proper course of action is to adjourn the matter until another bench renders its judgment on similar matters. Therefore, accordingly we adjourn the hearing of this matter for six months to enable another bench to deliver the judgement in another pending matter.

"As a consequence, the interim order staying the execution of petitioners (Veerappan aides) passed on February 18 shall continue" until further orders, the bench also comprising justices A R Dave and Vikramajit Sen said.

The bench noted that the subject matter of the petition was relating to the right of the death row convicts to get their sentence commuted to life imprisonment on account of delay of execution of their death sentence.

"This is the main question involved when this matter was taken by us. It was brought to our notice that other writ petitions involving the same issue were heard by a bench of two judges in which senior advocates Ram Jethmalani and T R Andhyarujina were requested as amicus curiae," the bench said.

Veerappan's elder brother Gnanaprakash and his aides Simon, Meesekar Madaiah and Bilavendran were awarded death sentence in 2004 in connection with a landmine blast at Palar in Karnataka in 1993 in which 22 police personnel were killed.

Their mercy petition was rejected by President Pranab Mukherjee on February 13 and they are presently lodged in a jail in Belgaum in Karnataka.

A TADA court in Mysore had in 2001 sentenced them to life term which was enhanced to death sentence by the apex court.

Gang leader Veerappan was killed in an encounter with the Tamil Nadu Police in October 2004.

The apex court also noted that the judgement in the writ petition heard by another bench on the issue was reserved on April 19, 2012.

The bench said it has been informed by Additional Solicitor General Haren Raval that while considering the two writ petitions, of Devender Pal Singh Bhullar and M N Das, the other bench had the occasion to consider similar matters in which the mercy petitions were pending before the President.

The CJI said that since another bench has already heard and reserved its judgement on the issue, there is a possibility that the pleas of Veerappan aides can be heard by the same bench also.

The court is hearing two petitions, out of which one was filed by the four convicts and the other by advocate Samik Narain, on their behalf.

Urging the apex court to intervene, the four death convicts pleaded that a decision on their mercy petition has been delayed by nine years and as per its earlier order they are entitled to seek remedy for undue long delay in the execution of the sentence of death.

"Nine years delay in disposal of the petitioners mercy petitions has given them a right to approach this Court or the High Court to seek a commutation of the sentence of death," the petition said.

On the last date of hearing, the court gave Narain the liberty to amend and rectify the petition after objections were raised on its maintainability by Attorney General G E Vahanvati who was asked to assist the court.

Senior advocate Colin Gonsalves, appearing for the four convicts, had said their execution should be stayed as another apex court bench had reserved its order on a plea for commuting death sentence to life imprisonment on the ground of delay in deciding mercy plea.