Anil Ambani's Reliance Group denied on Friday three executives charged in a multi-billion dollar telecom scandal had retracted their statements in a court case.
A police lawyer told the Supreme Court on Thursday the three jailed men had retracted their testimony taking responsibility for decisions made by a unit of Reliance Communications, according to the Press Trust of India (PTI).
Police have said a unit of Reliance Comm broke rules to gain valuable spectrum in 2008.
PTI reported that Indian federal police were examining Ambani's role in the telecoms licensing case. However, a CBI source told Reuters on Thursday the agency was currently collecting evidence and not yet directly investigating Ambani.
There was "no change in stand by any of the Reliance executives," Ambani's Reliance Group said in a statement, adding that neither the Reliance Communications unit nor the founder group benefited from telecoms licences issued in January 2008.
Shares in the Reliance Group companies, including Reliance Comm, Reliance Infrastructure, Reliance Power and Reliance Capital opened sharply lower on Friday, underperforming the broader market.
Reliance Comm shares were down 4.6% in late morning trade, while Reliance Infrastructure was down 5.5%, Reliance Capital was off 7% and Reliance Power was down 3.7%.
The sprawling telecoms scandal has affected several prominent companies and is the biggest of several to emerge in Prime Minister Manmohan Singh's second term. It has thrown a spotlight on leading industrialists and politicians and slowed Singh's agenda of economic reforms.
India's No.2 mobile carrier, Reliance Communications, is controlled by Ambani. The lawyer said the police were trying to establish who the real beneficiaries of the alleged scam were, and said they were looking at Ambani himself, according to PTI.
Ambani, India's eighth-richest man according to Forbes, is the highest-profile executive to be touched by investigation. The 52-year-old tycoon was questioned by police earlier this year, but denies any wrongdoing and has not been charged with any crime.
Police accuse the Reliance Group unit and the executives of setting up a front company to sidestep rules limiting stakeholdings in telecoms companies.