[1/3] Indian billionaire Gautam Adani speaks during an interview with Reuters at his office in the western Indian city of Ahmedabad April 2, 2014.
Last week, the group's flagship entity Adani Enterprises (ADEL.NS) pulled its secondary share offering, India's largest ever, because of the sharp selloff.
Adani has said Monarch was selected for previous share sales "for their credentials and ability to tap into the retail market".
On Elara, Adani has said "innuendoes" that the firm was in any manner related to the conglomerate founders were incorrect.
The federal corporate affairs ministry, responsible for regulating Indian businesses, has briefed officials in Modi's office and been in touch with SEBI, the market regulator, one of the officials said.