Investigation agencies have widened their net on India's premiere financial institutions in connection with the PNB scam as the Mumbai wing of Serious Fraud Investigation Office (SFIO) has issued a summons to ICICI CEO Chanda Kochar and Axis Bank CEO Shikha Sharma over a consortium of 31 banks lending Rs. 5,280 crore to Mehul Choksi's Gitanjali Gems.

The SFIO  has written to all the banks in the consortium as well as senior officials from the banks to explain the circumstances under which the loans were sanctioned to them.

The 31 banks include 20 public sector banks and nine private and multinational banks. ICICI Bank is the leading lender among the consortium of 31 banks, extending upto 6,800 crore to Gitanjali Gems.

Meanwhile, VP of the Gitanjali group, Vipul Chitalia was arrested by CBI on Tuesday and was reportedly accused of being the brain behind the Nirav Modi scam along with CMD director Mehul Choksi.