These will be the first set of cases registered in the preliminary enquiry by the agency on reference from the Central Vigilance Commission which had asked it to probe the allocation of captive coal mines from 1993 to 2004.
Incidentally, the NDA was in power at the Centre for almost half of this eleven-year period.
The agency has already registered nine FIRs in connection with the captive coal block allocations between the period of 2006 to 2009.
CBI sources said in the new cases, prima-facie evidence also points towards alleged involvement of some government officials who scrutinised applications of beneficiary companies at various levels.
The agency is scrutinising documents received from 24 companies which benefited during the period and is likely to start filing FIRs in batches, they said.
The sources, however, refused to give details of companies as it might affect their planned search operations but indicated that some action might be taken against them this week.
The allocation of coal blocks to private companies for captive use started in 1993 when Coal Mines (Nationalisation) Act, 1973, was amended with the objective of attracting private investments in specified end uses such as power, cement and steel.
Coal Minister Shri Prakash Jaiswal, along with seven MPs, has sought probe since 1993 and submitted a list of 24 beneficiary companies, some of which have got captive coal blocks as part of joint ventures with state government, which would be under probe of the agency, the sources said.