Credit Suisse’s (NYSE:CS) offshore business is under investigation with the U.S. Justice Department due to business with wealthy American clients as part of a larger search about U.S. tax evaders.The company learned about the investigation on Thursday and is willing to work together with U.S. authorities surrounded by the restrictions of secrecy in Swiss banking.In a statement by Credit Suisse, "The investigation concerns historical private banking services provided on a cross-border basis to U.S. persons. It has been reported that the U.S. authorities are conducting a broader industry inquiry."Observers saw anticipation of a proper investigation after three former and one recent employee of the bank were charged by U.S. authorities last February on charges of conspiring to assist American tax cheats.Credit Suisse Group has a potential upside of 54.1% based on a current price of $37.05 and an average consensus analyst price target of $57.1.