Key legal question
Whether the appeal against the annulment of the summons was admissible under Art. 93(1)(a) BGG.
Extracted holding
The challenged decision did not cause an irreparable legal disadvantage; the appeal could not be heard.
Extracted reasoning
Refusal of evidentiary steps in criminal investigation proceedings normally does not satisfy Art. 93(1)(a) BGG. Any evidence request can be renewed later, and a rogatory examination remained possible. No imminent loss of evidence was shown.