Stonewall us if you must but please state your reasons for preventing our investigators from questioning senior officials in corruption cases. This is the essence of a plea the Central Bureau of Investigation has made in its affidavit to the Supreme Court in the ongoing probe into the questionable allocation of coal blocks, highly placed sources told The Hindu.

The CBI has sought a specific remedy from the court, suggesting that ministers who deny the agency permission to question senior government officials be obliged to provide reasons for doing so. Under current rules, a minister can tell the CBI to back off without offering any explanation.

If the CBI’s recommendation, as enunciated in its affidavit, is accepted by the Supreme Court, it would, in effect, mean that Prime Minister Manmohan Singh could be asked to state his reasons in case the PMO denies the agency permission to question its officials in connection with the coal scam. The affidavit was filed last month after the Supreme Court declared its intention to “liberate the CBI from external extraneous influences.”

The CBI is learnt to have stated in its affidavit that the present system of seeking approval to question government officials was highly discriminatory. For questioning officers of the level of joint secretary and above, it is mandatory to seek the approval of line ministers, which is often refused without providing any reason.

Earlier this week, the CBI hit a dead-end when the Ministry for Corporate Affairs — the nodal ministry for the Competition Commission of India — said investigators could not question the former Coal Secretary, H.C. Gupta, currently a member of the CCI.

The agency is believed to have suggested that this loophole be plugged and the line minister be obliged to respond with a speaking order in which a specific reason is given in case permission to question senior officials is denied.

The CBI’s argument assumes special significance because the agency has now sought approval to question some PMO officials in connection with the coal allocation matter, highly placed sources said. If permission is denied, the agency wants the Prime Minister to put his reasons on the table.

CBI investigators have also not given up on questioning Mr. Gupta, who is being dubbed as a key link in the alleged irregularities in the allocation of coal mines when the Coal Ministry was under the charge of the Prime Minister. The BJP has accused the government of blocking his questioning in an attempt to shield Dr. Singh.

The CBI took up the coal case in the wake of a Comptroller and Auditor General report which said a whopping revenue loss of Rs 1.86 lakh crore had been caused by the parcelling out of coal blocks to select companies.

In the ongoing probe into the allotment of coal blocks between 2006 and 2009, the CBI has so far registered 11 regular cases (RCs). During this period, 68 coal blocks were allotted to 151 companies and the files of some of them have gone missing. The CBI has so far questioned former Union Ministers Santosh Bagrodia and D. Narayan Rao, and Congress member of the Rajya Sabha Vijay Darda.

In the first week of May, CBI Director Ranjit Sinha admitted before the Supreme Court that certain changes were made in the agency’s draft investigation report on suggestions given by the then Union Law Minister Ashwani Kumar, Attorney-General G. E. Vahnavati and officials of the PMO and Coal Ministry.

The Supreme Court had then pointed out that the whole direction of the probe had been changed in this case. Insisting that the CBI be insulated from extraneous influence and made an independent organisation, the court said the government should put in place a law before the next date of hearing (July 10), pointing out that the government need not wait for Parliament approval as there were other methods to achieve the objective.