According to Job Tilman, a Frankfurt prosecutor, managers and staff of the bank are suspected of helping their customers withhold tax by hiding money in branches abroad.
The inspectors turned up unannounced yesterday morning at Deutsche's headquarters in Frankfurt, as well as in branches in Freiburg, Dusseldorf and Kassel.
The authorities are focusing on cash transfers to Deutsche branches in Luxembourg and Switzerland. Investigators suspect that customers had switched money and securities abroad anonymously, with the help of bank employees. They believe that neither the deposits nor their interest earnings had been declared in Germany.
A Deutsche Bank spokesman said: "We won't comment, but are co-operating in line with requirements, although we must protect our customers' confidentiality. It is not unusual that we are being searched after many other banks were already investigated."
Attempts to locate untaxed earnings spirited out of Germany have been going on since 1994. Two other large banks, Dresdner and Commerzbank, have already been subjected to similar raids, forcing the resignation of senior executives.