At least five crucial files related to allotment of coal blocks during 2006-09 have not been received by CBI that has again communicated to the coal ministry to make them available as soon as possible.
CBI sources said despite being given the specifics of the files they are yet to be furnished to the agency to expedite the probe in the coal allocation scam.
The agency has so far registered 13 cases related to allotment of coal blocks during the period 2006-09 for alleged misrepresentation of facts by the beneficiaries while applying of the blocks.
The sources said they are planning to register more cases in connection with its preliminary enquiry that relates to alleged irregularities in the allocation of coal blocks during the period.
The ministry had recently informed a Parliamentary committee that it is trying to locate lost and missing files on coal block allocation in the wake of Supreme Court slamming the Centre for not helping CBI with documents in its probe.
The sources in CBI said they had received a letter from coal secretary S.K. Srivastava addressed to the director CBI seeking details of the files that it requires for its probe.
They said they would again be giving details of the files soon to the ministry.
The agency is facing another problem with regards to its separate enquiry in the coal blocks allocated through joint venture routes as 19 of the 20 state governments it approached have not given their consent to probe the irregularities.
In its status report filed on March 8 before the Supreme Court, the CBI had said that the coal blocks allocation during 2006-09 was done without verifying the credentials of companies which allegedly misrepresented facts about themselves and no rationale was given by the coal ministry in giving coal blocks to them.