According to government sources, Attorney General Mukul Rohtagi asked the CBI to file the chargesheet, given the fact that there were enough evidence to book them.
Dayanidhi is accused of misusing his office as the Telecom Minister in 2011 and forcing the sale of cellphone operator Aircel to Maxis, owned by T Ananda Krishnan.
CBI cliams that in return the Malaysian Group invested Rs. 650 crores in the Sun TV Group, owned by Mr Maran's brother, Kalanithi.
C Sivasankaran, who owned Aircel at that time confirmed that Maran did not let any critical licenses be given to Aircel in order to force him to give in.
Post the merger, Aircel started getting clearances at jet speed.
The Attorney General was forced to step in after differences occurred between the CBI director Ranjit Sinha and the agency's Director of Prosecution, which led to a delay in a charge-sheet in the case.
Mr Sinha deduced that the evidence against Dayanidhi Maran was insufficient.
The matter landed with former Solicitor General Mohan Parasaran earlier this year, who referred it to the new government.