The Central Bureau of Investigation on Wednesday summoned billionaire Anil Ambani, who controls India's second largest mobile phone operator Reliance Comm, over a probe into the 2G corruption case, television channels said.
The CBI have summoned several executives from the sector to answer questions regarding a probe into whether there were any irregularities in the sale of lucrative licences below market prices in 2007-2008.
A Raja, former telecoms minister, has already been arrested for suspected involvement as has a senior executive of one of the companies in question.
A spokesman from Reliance Communications did not have an immediate comment when asked by Reuters. A CBI spokesman was not immediately available for comment.
Reliance Communications has in the past denied any wrongdoing related to the issuing of licences.