Basel-Stadt Court of Appeal: SkyECC data absolutely inadmissible for violation of Swiss sovereignty

In its judgment of 3 October 2025 the Court of Appeal of the Canton of Basel-Stadt held that SkyECC chats are absolutely inadmissible and ordered their removal from the file. Departing from the trial court's reliance on mutual trust, it examined the French evidence-gathering itself. Following the Zurich High Court (SB240422-O), it found that the man-in-the-middle push message took effect on the phone in Switzerland without mutual legal assistance, which violated Swiss territorial sovereignty (BGE 146 IV 36; Art. 141(5) CrimPC). The court gave two further grounds. The bulk interception of the servers lacked the individualised suspicion required by Art. 269 CrimPC and amounted to a fishing expedition contrary to Swiss ordre public. The defence also had no access to the raw data beyond the triaged extracts, which violates the right to be heard (Art. 29(2) Federal Constitution, Art. 107 CrimPC). The conviction was upheld on other evidence.