The probe investigates so-called mirror trades, where the bank’s Russian clients bought stocks in rubles, and through simultaneous transactions in London, bought the same stocks in U.S. dollars, thereby moving funds out of Russia without informing authorities, Bloomberg reported. Last month, The New York State Department of Financial Services (DFS) sought detailed information from Deutsche Bank on possible money-laundering transactions by some of its clients in Russia that could exceed $6 billion in total, a source familiar with the matter told Reuters.