Germany is to buy a CD of confidential data on 1,500 customers at a Swiss bank this weekend, a media report said.
The deal, which is expected to reveal wealthy German nationals evading millions of euros of tax payments, is to be concluded in France, Focus news magazine reported Saturday.
The whistleblower at the bank feared arrest and a confiscation of the data CD if he travelled to Germany, the magazine said.
Meanwhile France has offered Germany access to confidential data on tax-evaders holding accounts with HSBC Private Bank in Geneva, Focus reported.
The data, which was handed to the French authorities by a former IT worker at HSBC, includes numerous German clients, French lawyer Eric de Montgolfier told the magazine.
Montgolfier had received the data, exposing 130,000 HSBC clients, from former HSBC employee Herve Falciani.
Falciani had also reportedly offered the information to German intelligence agents, but never sold them the information.
Germany's decision to buy the stolen data angered the Swiss authorities, who are in the process of negotiating a new double taxation agreement with their northern neighbours.