The CBI is gearing up to question senior officials of the Finance Ministry in connection with the Aircel-Maxis case to ascertain how the deal got through the Foreign Investment Promotion Board (FIPB).

As it plans to file the charge sheet later this week, the agency wants to question the officials who were part of the FIPB clearance process. CBI officials are maintaining that they have not identified suspects in the case.

The officials will be asked to explain the rationale behind giving clearance to the deal, which has now landed in controversy after Aircel owner C Sivasankaran alleged that he was coerced by then Telecom Minister Dayanidhi Maran to sell his company to Maxis.

The case registered by the CBI in 2011 has found its way into headlines once again after new Attorney General Mukul Rohtagi cleared the hurdles for chargesheeting Dayanidhi and his brother Kalanidhi Maran, the promoters of Chennai-based Sun Group, under charges of criminal conspiracy and provisions of Prevention of Corruption Act.

The Marans are accused of coercing Sivasankaran to sell his stake to Maxis, owned by Malaysian businessman T Ananda Krishnan. The Malaysian businessman later invested Rs 650 crore in Sun TV network, which Marans’ critics allege, is a quid pro quo for allocating spectrum to Maxis.

It was also alleged that the then Finance Minister P Chidambaram, who was heading the Foreign Investment Promotion Board (FIPB), cleared the takeover violating norms.

Chidambaram had denied the charges against him and his son Karti, who was alleged to have been benefited from the deal. Senior BJP leader Subramanian Swamy has also recently written to Prime Minister Narendra Modi seeking speedy investigation into the allegations against Marans and Chidambaram.

Though a charge sheet is being filed this week, CBI officials said they could include other names in the supplementary charge sheets.

If any wrongdoing is found during investigations, they said, the Finance Ministry officials would find their names in the supplementary charge sheets.

There was pressure on the CBI in the recent past to investigate the role of Chidambaram in giving government clearance for the deal.