The Central Bureau of Investigation (CBI) Tuesday filed a revised closure report in a coal block allocation case involving industrialist Kumar Mangalam Birla and others in a Delhi court.The report was filed before Special Judge Bharat Parashar who posted the matter for Nov 10. The court, during the last hearing, had sought clarifications from the investigating agency whether an element of criminality was involved while allocating the coal blocks to the Birla-promoted Hindalco. The CBI had booked Birla, former coal secretary P.C. Parakh and others, on charges of criminal conspiracy and corruption in the allocation of coal blocks in October 2013.But it filed a closure report in the case Aug 28, saying: "The evidence collected during investigations did not substantiate the allegations levelled against the persons named in the FIR (first information report)."The court had earlier also sought to know on what basis CBI had drawn such a conclusion to close the case and what kind of investigation it has conducted.