Why the time limit matters
The time limit is the guarantee against an endless investigation. An extension must be justified and formalised. Under article 351 of the Criminal Procedure Code, the investigator gives the prosecutor the request for an extension at least ten days before the time limit ends. The time spent reading the case materials, and the time while the investigation is suspended, do not count towards the time limit.
Your rights
To know about the decisions taken in the case; to appeal the acts and decisions of the investigator, the prosecutor and the court; to read the case materials to the extent the law allows.
If nothing happens
You can complain against the acts and decisions of the investigator to the head of the investigation unit, or to the prosecutor who supervises the investigation. You complain against the acts of the prosecutor to the higher prosecutor. In the complaint, state exactly which act was not performed.
Advice
File every request in two copies and get a mark of receipt. These copies are what proves the inaction.