The Central Bureau of Investigation on Monday filed a curative petition in the Supreme Court seeking restoration of stringent charge of culpable homicide not amounting to murder, which attracts maximum punishment of a ten-year jail term, against the accused in the 1984 Bhopal Gas tragedy case.

The petition, settled by Attorney General G E Vahanvati, has sought reconsideration of the September 13, 1996 apex court judgement which had diluted the charges against former Union Carbide India [Images] Chairman Keshub Mahindra and six others.

"We have asked the court to reconsider the decision of the apex court which diluted the charges against the accused. We have sought a direction from the court to restore section 304 part-II of the IPC," advocate Devdatt Kamat, who drafted the over 500-page curative petition, said.

Besides Mahindra, Vijay Gokhale, the then managing director of UCIL, Kishore Kamdar, the then vice president, J N Mukund, the then works manager, S P Choudhary, the then production manager, K V Shetty, the then plant superintendent and S I Quereshi, the then production assistant were convicted and sentenced to two years jail term by the trial court in Bhopal on June 7.

The trial court verdict had sparked an outrage with activists and political parties seeking an appeal against it, maintaining that they had been tried under a less provision of law for the tragedy that left 15,000 people dead and thousands maimed.

All the accused were tried under section 304A of the Indian Penal Code which attracts the maximum punishment of two years' imprisonment for causing death by rash and negligent act.

The charge under section 304 part-II was diluted to section 304A by the bench comprising the then Chief Justice A M Ahmadi and Justice S B Majmudar.

In the curative petition, the CBI said the 1996 verdict diluting charges suffered from serious errors.