The sources said the agency has received all the relevant files and detailed examination of coal ministry officials has also been done.
Since probe does not indicate that public servants were intentionally withholding these records from probe, the agency might seek permission from the apex court to close these inquiries, they said.
CBI had registered two enquiries to look into the issue of missing files on coal block allocations from the Coal Ministry. One was for the period between 1993 and 2005 and another is for the period 2006-09.
The slow CBI probe into the coal scam had come under sharp criticism of the court which had said the agency was still in the "first gear" and needed to pick up speed.
"You (CBI) have to pick up some speed. The pace of inquiry is not good. You are still driving in the first gear. Yours is a huge task and all these need to reach the logical conclusion," a bench headed by Justice R M Lodha had said.
