La Casa de Corbat is only boringnorth of the border.

Citigroup Inc. said as much as $400 million was stolen from its Mexico unit in what the bank's chief executive called a "despicable crime."

The New York bank announced Friday that it was cutting its fourth-quarter and full-year results by about $235 million after finding allegedly fraudulent billings at its Mexico unit, Banco Nacional de Mexico, or Banamex….

"Only two weeks ago I wrote to you about the absolute need for everyone at this firm to act in accordance with the highest ethical standards," Mr. Corbat wrote to employees in a memo Friday. "We now have a galling example of what happens when people fail this basic requirement…."

On Feb. 11, Citigroup said, it learned that Oceanografía had been suspended from being awarded new Mexican government contracts. That triggered a review by the bank of its relationship with Oceanografía.

Citigroup said it consulted with Pemex, which told it that a significant portion of the amounts allegedly owed to Banamex were based on fraudulent invoices from Oceanografía.

Citigroup Takes $400 Million Hit, Alleging Fraud [WSJ]
Citigroup: U.S. Sought Information From Mexico Unit [WSJ]
Mexico Said to Interview Citigroup Workers in Fraud Probe [Bloomberg]