Sky-ECC data in Zurich drug case: Federal Court does not rule on complaint
The Federal Court has declined to rule on a complaint by the Zurich public prosecutor's office regarding the admissibility of Sky-ECC data. The question remains open until the final judgment.
Federal Court leaves Sky-ECC question in Zurich drug proceedings open for now
Whether Swiss law enforcement authorities may use data from the encrypted communications service Sky-ECC as evidence remains unclear for now. According to a judgment published on Friday, the Federal Court has declined to rule on a complaint by the Zurich senior public prosecutor's office, as reported by Nau.ch.
The starting point is a drug case before the Dielsdorf District Court: In January 2024, the court convicted a man of multiple aggravated violations of the Narcotics Act to a custodial sentence of ten years and nine months. In addition, he was ordered to pay a compensation claim of 800,000 Swiss francs and a ten-year entry ban was imposed.
In the appeal proceedings, the Zurich Higher Court, at the defendant's request, split the proceedings and initially dealt exclusively with the question of the admissibility of evidence. It decided not to admit the Sky-ECC data — a decision against which the public prosecutor's office appealed to the Federal Court.
Sky-ECC was an encrypted messaging service whose communications were routed via servers in Roubaix, France, and was used by criminals for their activities. A European investigation team from France, Belgium and the Netherlands, supported by Eurojust and Europol, was able to decrypt the messages and subsequently transmitted the data to Swiss authorities. The guilty verdicts of the Dielsdorf District Court were largely based on this material.
The Federal Court nonetheless declined to rule on the complaint — for a procedural reason: The Higher Court's decision from August 2025 is merely an interlocutory order, which under applicable law cannot be challenged separately. A challenge to the highest Swiss court is only possible after completion of the main hearing and submission of a complete judgment.
There is also a further procedural problem: The Higher Court split the proceedings in a manner not provided for in the Criminal Procedure Code. The Federal Court notes that even in procedurally permissible case divisions, interlocutory orders cannot be challenged individually. All the more so when the decision is based on an inadmissible division.
The Zurich public prosecutor's office will therefore only be able to challenge the inadmissibility of the Sky-ECC data established by the Higher Court before the Federal Court after the final judgment.
Source: Nau.ch