The allotment of iron ore mines at Ankua, Singhbhum district of Jharkhand to Tata steel is also being enquired into, they said.
They said although the agency has so far not found any criminality in its enquiries but it will seek clarification from Tata and Mistry over some issues regarding tapped conversations where references were made about these deals.
They said a journalist from a TV channel and a senior executive of a leading newspaper group have already been examined by the agency.
Besides, executives of Reliance, Unitech and Tata Motors have also been examined by the agency in connection with its enquiries.
CBI has registered 14 preliminary enquiries into issues of alleged corruption arising in the communications of Radia intercepted by the Income Tax department.
