“State prosecutors have launched 1,100 investigations against customers and staff of Credit Suisse,” Dirk Negenborn, spokesman for prosecutors in Duesseldorf, western Germany, told AFP.
“The Credit Suisse clients have investments in total of around 1.2 billion euros (1.6 billion dollars).”
He said the total amount of tax owed to the authorities was unclear, but according to several sources the tax authorities stand to recover up to 400 million euros.
Those targeted by authorities can expect to be raided soon, another spokesman said. They include wealthy Germans in several states including Bavaria and Baden-Wuerttemberg in the south of the country.
“Credit Suisse will neither confirm nor comment on the information as it has not had any official contact with the German authorities,” said Marc Dosch.
The probe stems from a CD with confidential banking data sold to the German state of North Rhine-Westphalia, Germany’s most populous state, the Frankfurter Rundschau newspaper reported.
In February, the state bought stolen information on 1,500 suspected German tax cheats holding bank accounts in Switzerland. German press reports have said the state shelled out 2.5 million euros for the CD.
The federal government of Chancellor Angela Merkel in early February gave the green light for North Rhine-Westphalia, home to Germany’s historic industrial heartland, the Ruhr district, to buy the Swiss CD.
The Sueddeutsche Zeitung daily reported in its Saturday edition that over 10,000 people have surrendered to authorities since the purchase.
The saga prompted a high-profile debate in Germany about paying for illicit data as well as a souring of its relations with its Alpine neighbour Switzerland.
In 2008, a similar deal netted a long list of names and bank accounts in the principality of Liechtenstein which let officials recover around 200 million euros in unpaid taxes and led to the arrest of the head of the logistics group Deutsche Post.
The saga put Liechtenstein and other tax havens including Switzerland in the firing line of international efforts against offshore banking havens and tax dodgers.
Fellow Swiss banking giant UBS has found itself in hot water for allegedly helping rich Americans hide money from the taxman.
In a state-brokered settlement in August 2009, UBS warded off a bruising US government lawsuit by agreeing to hand over secret details on about 4,450 clients and US taxpayers.