An all-out war has broken out between Citigroup CEO Vikram Pandit and a prominent securities analyst who is saying that the big bank may be cooking the books by inflating its earnings through an accounting gimmick, FOX Business Network has learned.

The analyst, Mike Mayo, of the securities firm CLSA, has been telling investors that Citigroup (C: 3.72 ,+0.02 ,+0.68%) should take a writedown, or a loss on some $50 billion of “deferred-tax assets,” or DTAs. That is a tax credit the firm has on its financial statement that Mayo says is inflating profits at the big bank by as much as $10 billion.  READ MORE