Swiss Federal Supreme Court Declines to Review Exclusion of SkyECC Data in Zurich Drug Trafficking Case

(Judgment 7B_1429/2025 of 5 August 2026)

In its interim decision of 15 August 2025, the Zurich Court of Appeal ruled that the SkyECC data in the underlying drug-trafficking proceedings was absolutely inadmissible. The court ordered the data to be removed from the case file, holding that its use breached two distinct principles: the decryption process infringed Switzerland's territorial sovereignty, and, independently, the underlying covert surveillance measure had not been backed by sufficient individualised suspicion, as Swiss law requires for such measures.

The ruling was issued as the outcome of the first of two phases into which the appellate hearing had been split, at the defence's request. The initial phase, held in June 2025, was confined exclusively to the question of the SkyECC data's admissibility.

The Zurich prosecution authorities challenged this interim ruling before the Federal Supreme Court, arguing that the excluded data was decisive for several of the drug-trafficking counts and that they could not meaningfully argue their case at the resumed appeal hearing without reference to it.

In its judgment of 5 August 2026, a five-judge panel of the Federal Supreme Court declined to enter into the merits of the appeal. The court held that a ruling on evidence admissibility issued at the appellate stage, before the underlying criminal case has been finally decided, does not by itself cause the prosecution the kind of irreparable harm that would justify an immediate appeal to the Federal Supreme Court. It distinguished this from situations where evidence is excluded during the pretrial investigation itself, since here the prosecution had already been able to complete its investigation and bring formal charges, and the trial court had treated the evidence as admissible; with the case now before the appellate court, the prosecution remains free to raise the admissibility

question again once a final judgment has been issued. This finding was reinforced by a further, procedural consideration concerning the manner in which the appellate hearing had been divided into two phases — a question of Swiss criminal procedure not addressed in further detail here.

As a result, the Federal Supreme Court did not review the substance of the Zurich Court of Appeal's finding on SkyECC admissibility, and the prosecution's appeal was dismissed without a decision on the merits.

Attention, however, remains on the Federal Supreme Court. A case raising the same admissibility question, decided by the Basel Court of Appeal in October 2025, is currently pending there as well. Unlike the Zurich case, where only an interim ruling was under challenge, the Basel proceedings reach the Federal Supreme Court by way of a final decision — so the Court is expected to enter into the merits there and to rule on the substance of the SkyECC admissibility question.

7B_1429_2025 05.08.2026.pdf

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(Case citation: Swiss Federal Supreme Court, Judgment 7B_1429/2025 of 5 August 2026, on appeal from the interim decision of the Zurich Court of Appeal, II. Strafkammer, of 15 August 2025.)