Theft of documents happening for long : Rajnath Singh

"No guilty person would be spared and strictest punishment would be given to them," Singh told reporters while speaking on the arrest of  government employees and top  corporate executives in connection with the  theft of documents from the ministry of petroleum and natural gas.

"...But it is certain that such things have been going on for a long time and that is why the situation has reached such a stage. If we were not alert, these things would not have come to light," he said.

On Thursday, police arrested five people - two petroleum ministry employees and three others - for stealing documents and leaking them to corporate houses.

With seven arrests on Friday, the total number of those held rose to 12.

According to the police complaint, the stolen documents included inputs for the Union Budget 2015 and a letter concerning the Prime Minister's Office. The documents were also related to the power and coal ministries, police said.

Those arrested include five corporate executives -Shailesh Saxena of Reliance Industries Ltd, Vinay Kumar of Essar, KK Naik of Cairns, Subhash Chandra of Jubilant Energy and Rishi Anand of ADAG Reliance.

Replying a question, Singh did not rule out that middlemen and government officials were in cahoots and more ministries could be investigated. "It is possible. I am not ruling out any possibility. Delhi Police is investigating the whole issue. I think the issue will come to light very soon," he said.

Meanwhile, Delhi chief minister Arvind Kejriwal, on his part, said Delhi Police should now zero in on the "top people" benefiting from the leak.

"Compliments (to the) Delhi Police for busting espionage racket. During interrogation, police should try to reach top
people, who would benefit from leaked info," he tweeted.

The ruling Aam Aadmi Party (AAP) on Friday had demanded setting up of a commission to probe the matter in a time-bound manner.