As part of the investigation, the SFIO has issued summons to heads of over 30 banks that have exposure to companies of diamond traders Nirav Modi and Mehul Choksi.
With Axis Bank and ICICI Bank complying with the SFIO summons, other lenders are likely to follow the suit.
"We have summoned Mehta (the head of the beleaguered bank) and he is expected to appear before us tomorrow," said an SFIO official.
A team from Axis Bank, led by deputy managing director V Srinivasan and executives from the trade and transactions department, today went to the SFIO's office.
On February 14, PNB had said it detected fraudulent transactions worth USD 1.77 billion (Rs 11,400 crore) at one of its branches in Mumbai.
The lender on February 27, however, said the amount of fraudulent transactions could be Rs 1,300 crore more.
The transactions were carried by diamond jeweller Nirav Modi by acquiring fraudulent letters of undertaking (LoU) from the lender's Brady House branch in Mumbai to secure overseas credit from other Indian lenders.
The CBI has so far arrested over a dozen of persons, including former and current officials of PNB and companies related to Nirav Modi and Mehul Choksi.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)