The agency has moved an application before the special CBI court here seeking recording of statements of the Anil Dhirubhai Ambani Group Chairman and his spouse as witnesses.
Although the agency has recorded the statement of Anil while investigating the case, it had not produced him before the court as a witness.
"We sought the court's permission to produce Anil and Tina Ambani as witnesses. We feel that it will bolster our case," Sinha told PTI.
Three top executives of the ADAG group-- Gautam Doshi, Hari Nair and Surendra Pipara- are accused in the ongoing case.
The agency has alleged that Shahid Balwa and Vivek Goenka promoted Swan Telecom Private Limited, an accused firm in the 2G case, was a front of Reliance ADAG.
The CBI claimed the move was aimed at getting telecom licenses even though existing players were barred from getting fresh ones.