The investigation focuses on a leaked list of more than 50,000 phone numbers from across the world.
As many as 44 companies including Anil Ambani's nice group companies, Essel, Jet Airways, Vodafone accounted for bad loans of Rs 34,000 crore of Yes Bank.
Ambani's group companies are stated to have taken loans of about Rs 12,800 crore from the bank that turned NPAs.
Ambani got the charge of RCom after property division between him and his elder brother Mukesh Ambani in 2005.
Bollywood celebrities including Shah Rukh Khan, Aishwarya Rai Bachchan and Abhishek Bachchan and Shahid Kapoor and Mira Rajput attended the gala function.
The Companies Act 2013 has a section that enables interested parties to file a class action suits. But so far no case has been filed under this provision.
Ambani said these repayments, aggregating to Rs 35,400 crore, were made without any additional liquidity support from any lender.
Rebutting Rahul Gandhi's charge that Anil Ambani is a crony capitalist, Reliance Group said the Congress president is continuing his campaign of 'calumny, disinformation, distortion and malicious lies.'
The Congress alleged that the tax concession for Ambani was due to Modi 'kripa' (blessings) while the Left parties said the Prime Minister's Office "must own up to this".
Anil Ambani's Reliance Atlantic Flag France lands in soup after newspaper report.