After a week that saw Deutsche Bank's shares hit a record low over growing concerns about its finances, the German-based lender's troubles persisted into the weekend with a technical glitch that locked customers out of their accounts.
Deutsche Bank told Handelsblatt newspaper that "only a few" customers were briefly affected by the malfunction on Saturday. It was the third such mishap to strike customer accounts in recent months.
Although the scale of the problem was limited, it came as the bank is trying to allay fears over its stability.
Its stock plunged on news that the US Justice Department is threatening to impose a multi-billion-dollar fine linked to the sale of mortgage-backed securities in the run-up to the 2008 financial crisis.
Worries continued to grow on Thursday after media reports said 10 US hedge funds moving their business out of the bank.
German Chancellor Angela Merkel's government was forced to join Deutsche Bank's chief executive John Cryan in rejecting reports that Berlin had drawn up an emergency rescue plan for the bank.