NEW DELHI (Reuters) - India’s top court on Wednesday gave the government 10 days to disclose the details of an $8.7-billion military jet deal with France’s Dassault Aviation to former ministers and an activist who say the information should be in the public domain.

Prime Minister Narendra Modi’s deal for the purchase of 36 Rafale planes has become a major political controversy because of the escalating price and a decision to pick billionaire Anil Ambani’s Reliance Defence as a domestic partner.

Reliance, which has no aeronautical expertise, was chosen instead of the state-run Hindustan Aeronautics, which has a long history of making planes.

The Supreme Court ruled that if the material was strategic in nature or involved national security, the government might choose not to reveal it to the petitioners, but will instead have to furnish it to the court in a sealed package.

“We ask the center to give details of the pricing and strategic details of Rafale fighter aircraft in sealed cover in 10 days,” Chief Justice Ranjan Gogoi said, referring to the government.

The ruling came in a hearing on petitions including a joint plea by former government ministers Yashwant Sinha and Arun Shourie, along with lawyer and activist Prashant Bhushan, on the jet deal.

“There should be a court-monitored Central Bureau of Investigation probe into the Rafale deals,” Bhushan told the panel of three judges during arguments.

The court’s order was a “very, very substantial step forward,” another petitioner, Arun Shourie, told television channel NDTV after the order.

“Confidentiality does not relate to price, only technical specifications,” he added. “It will be subject to challenge. It will be difficult to say pricing is confidential.”

The Official Secrets Act covers most of the details regarding the Rafale jets, including pricing, and it would not be possible for the government to share them with anyone, Attorney General K.K. Venugopal, representing the government, told the court.

The panel said that if the government felt the pricing of the Rafale jet could not be shared with the court, even in a sealed cover, it should say so in an affidavit.

The Supreme Court also asked the government to give copies of the decision-making process to the petitioners.