Federal and state prosecutors are investigating Deutsche Bank [1] and several other global banks over accusations that they funneled billions of dollars through their American branches for Iran, Sudan and other sanctioned nations, according to law enforcement officials with knowledge of the cases.

Neil M. Barofsky, the former inspector general for the Treasury’s bank bailout fund, said fears that banks would not cooperate were overblown because it was “in their best interest to cooperate to avoid criminal prosecution and to keep their license.”