BOCHUM – The German prosecutor’s office in the western city of Bochum announced it had uncovered proof of massive tax evasion, with billions of undeclared euros deposited by German investors in Swiss bank accounts.

The prosecutor in the state of North Rhine Westphalia analyzed the contents of a CD with data from German clients, including 750 foundations and 550 individuals. The data showed secret accounts with Swiss banking giant UBS totaling 2.9 billion euros. The foundations alone are alleged to have evaded 204 million euros in German taxes.

Since 2007, the western state of North Rhine Westphalia has been buying CDs containing information about alleged tax evaders. The practice by the state’s Social Democratic Party (SPD)-led government has met with criticism from Germany’s Finance Minister Wolfgang Schäuble, who believes it adversely affects the chances of getting a global German/Swiss tax agreement signed.

Meanwhile, the SPD and Greens believe the draft agreement Schäuble has negotiated with the Swiss is too lax and are blocking its passage in federal parliament.

There are no official estimates of how much “black” money Germans have in Swiss accounts, though this latest probe, one of the largest to date, offers further signs that the amounts may be enormous. Thomas Eigenthaler, the head of the Deutsche Steuergewerkschaft (a trade union of workers in the finance and taxation sectors) told Süddeutsche Zeitung he believed the total amount was somewhere around 150 billion euros.

According to the prosecutor’s office, only 135 of the 1,300 accounts named on the UBS CD had voluntarily disclosed their Swiss account to German tax authorities as they have the option to do.

The UBS CD is said to have cost 3.5 million euros. Unlike earlier CDs acquired by the state of North Rhine Westphalia, it offers little indication of active cooperation by bank employees to help account-holders evade taxes.