The clients allegedly bought insurance policies at a Bermuda-based subsidiary of the Swiss bank between 2005 and 2009, the report said. These policies were sold to clients to earn tax-free interest on savings.

The WSJ reported that a Credit Suisse spokesperson said in a statement the bank has told clients who bought the policies to talk to their tax advisors. The spokesperson added that Credit Suisse told its clients they were responsible for determining their tax obligations when they bought the products, which were legal in Switzerland.

In November last year, Credit Suisse said it would hand over to the US Internal Revenue Service the names of clients suspected of evading US taxes – the bank did not give a specific figure, however.

The German investigation reopens an affair that Credit Suisse tried to close last September, when the bank agreed to a €150 million settlement to halt German investigations against bank employees, the WSJ said.

German and Swiss authorities have clashed over tax issues in recent years; German officials have used public funds to pay for data stolen from a Swiss bank, for example, raising questions about the extent to which governments will flout traditional rules of due process in their determination to obtain revenues.