Asked if it made sense to prevent banks in which Germany has taken a stake from doing active business in tax havens, Peer Steinbrueck told Berlin's taz newspaper: "The answer is yes."

Mr Steinbrueck declined to name which territories count as tax havens, but said: "We have already taken the first steps. We will see what happens in the next few weeks."

As part of a government rescue package, Germany has pledged to take a 25 per cent stake in Commerzbank.

Germany has been among the most vociferous opponents of so-called tax havens; it has even used data stolen by a former employee of  LGT, the Liechtenstein bank, in its hunt for German citizens evading taxes. At last week’s G20 summit in London, countries vowed to use sanctions if necessary to force offshore financial centres to co-operate in unmasking people who are not declaring their taxes.

Asked for more details on the anti-tax evasion measures, Mr Steinbrueck was quoted as saying: "I am not announcing anything here. Otherwise I'd have to spend another full day cleaning things up. Suffice it to say, we will take care of this problematic situation."

Commerzbank recently bought Dresdner Bank and has two private wealth management units in Switzerland, Commerzbank (Schweiz) and Dresdner Bank ( Switzerland). Dresdner is also the parent of Kleinwort Benson, the UK private bank.

Dresdner's Swiss unit has 14,000 wealth management clients, adding that this included manly non-German clients, a report by Reuters said. The unit had SFr9.4 billion ($8.2 billion) in client assets.

Exact figures for Commerzbank (Schweiz) AG were not available for 2008, a spokesman was reported as saying.