Microfilm containing the credit card details of tens of thousands of Germans has been anonymously sent in the post to the Frankfurter Rundschau newspaper.
According to local reports, the microfilm arrived at the paper in a cardboard box addressed to the editorial office.
It contained details of Landesbank Berlin customers, including names, addresses, credit card numbers and payment details. Co-branded cards held with Amazon, motoring group ADAC and Xbox are among those affected.
The cardboard box also included a bill of EUR71,400 for data processing services, addressed to Landesbank Berlin from IT firm Atos Worldline.
Police are investigating the matter and have advised Landesbank Berlin customers to check their accounts for inconsistencies.
Earlier this month German magazine WirtschaftsWoche reported that identity thieves were trying to sell the bank account details of 21 million people, for an asking price of EUR12 million.
Huge security breach for German credit cards - The Local