The case against LGT Treuhand, a former subsidiary of the LGT Group, was decided in January, according to a report in daily Süddeutsche Zeitung on Monday.
The Bad Homberg real estate developer, who was exposed for tax evasion when a bank employee sold the data to the German intelligence service for €4.5 million two years ago, has been awarded €7.3 million by the Vaduz district court.
The tax fraud scandal that followed the sale of the data pointed to some of Germany's top earners, among them former Deutsche Post boss Klaus Zumwinkel, who was convicted to two years probation and a hefty fine in January 2009. According to the paper, state prosecutors are still investigating up to half of the 845 cases involved.
The Liechtenstein court case has been closely watched by numerous other Germans who are also planning to sue the bank, the paper said.
They argue that if the bank had informed them that their data had been sold, they could have turned themselves in, receiving temporary amnesty and much lower fines.
The bank subsidiary's successor Fiduco Treuhand AG plans to appeal the case, the paper said.
Meanwhile a newly uncovered tax evasion scandal reached a new dimension last week, as German officials said more stolen data detailing up to 1,500 tax dodgers with funds stashed in Swiss accounts could mean some €400 million in unpaid taxes for state coffers.