In January 2022, during his skiing holiday in the Swiss Alps, Eckart Seith had a heavy burden lifted from his shoulders.

For years, the commercial lawyer from Stuttgart and well-known whistleblower had been at odds with the federal criminal justice system about the cum-ex transactions of Swiss banks.

In 2013, Seith received internal documents on cum-ex stock transactions from two employees of the Basel private bank Sarasin, including an opinion from the law firm Freshfields.

Bank Sarasin had handled such deals for investors such as the drugstore entrepreneur Erwin Müller via Luxembourg funds.

For Seith, it was at least clear back then that share group transactions around the dividend record date were illegal.

The lawyer, whose explosive tips to the Cologne public prosecutor's office led to numerous investigations, was initially threatened with imprisonment in Switzerland for industrial espionage and violations of Swiss banking secrecy.

But at the beginning of the year, the Zurich Higher Court overturned a first-instance judgment against Seith and two former bankers from 2019.

With this step, Seith saw his trust in Zurich's criminal justice system restored.

In the absence of charges, he also assumed that there would be no further hearing.

Far from it: As "Stuttgarter Nachrichten" and "Stuttgarter Zeitung" reported, the cum-ex reconnaissance officer has to face criminal proceedings in Switzerland again.

Following a complaint from the senior public prosecutor's office in the canton of Zurich, the criminal law department of the Federal Supreme Court in Lausanne decided weeks ago that the decision of the Supreme Court should be overturned and the matter referred to the lower court for further appeals.

The confirmed Seith the dpa.