India is taking steps to oust three bank executives, its banking secretary said on Monday, after police issued a list of people accused in the country's largest-ever bank fraud case.

Banking secretary Rajiv Kumar told media that a government nominee on the board of state-run Allahabad Bank would call a meeting to seek the removal of the lender's chief executive Usha Ananthasubramanian, who previously headed fraud-hit Punjab National Bank (PNB).

He also said state-run PNB had begun the process of removing two executive directors, without naming the executives or saying why the three were being ousted.

Separately, two sources familiar with the matter said the Central Bureau of Investigation (CBI) had named Ananthasubramanian, diamond jeweller Nirav Modi, and more than 20 others in a charge sheet filed at a Mumbai court on Monday

One of the sources said K.V. Brahmaji Rao and Sanjiv Sharan, both executive directors at PNB, were also named, marking the first batch of formal charges to be filed in the $2 billion fraud case.

The CBI charge sheet named 25 accused, including three firms, the source added.

PNB declined to comment on the filing of the charge sheet.