CBI sources said analysis of documents received from the coal ministry has shown one more instance of alleged irregularity.
The sources said a private company and some ex-officials of the coal ministry are under the scanner of the agency in connection with the alleged irregularities.
Refusing to give specifics of the case as it might hamper its search operations, the sources said the agency has completed its initial ground work and would register a case by the end of November.
The CBI has registered 14 FIRs so far in connection with the alleged graft in allocation of coal blocks in which AMR Iron and Steel, JLD Yavatmal Energy, Vini Iron and Steel Udyog, JAS Infrastructure Capital Pvt Ltd, Vikash Metals, Grace
Industries, Gagan Sponge, Jindal Steel and Power, Rathi Steel and Power Ltd, Jharkhand Ispat, Green Infrastructure, Kamal sponge, Pushp Steel and Hindalco have been named as accused.
The Supreme Court is monitoring the probe in the coal block allocation scam to "restore the larger public interest and confidence of the people into the case of this magnitude".
The court is scrutinising coal block allocation since 1993 on three PILs seeking cancellation of blocks on the ground that rules were flouted in giving away the natural resources and that certain companies were favoured in this process.
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