Starting the probe into alleged irregularities in coal block utilisation, officials of the Central Bureau of Investigation are likely to visit the Coal Ministry next week seeking clarification on some points.
The officials might collect some documents related to allocation and reports of utilisation of the coal blocks by private allottees, CBI sources said.
The agency has registered on Friday a preliminary enquiry, which is the first step to start a probe, against unknown persons.
Senior CBI officials made it clear that probe would primarily focus on the alleged irregularities in utilisation of coal blocks by allottee companies between 2006 and 2009.