The relevant part here is probably the last paragraph of section 25. It concerns the rules for admitting evidence that has not been given by the person themselves in an official investigation, and which has been obtained unlawfully. It is on page 97 in the linked PDF:
> [...] the court may use also evidence that has been obtained unlawfully unless such use would:
> * endanger the conduct of fair proceedings
> * taking into consideration the nature of the matter, the seriousness of the violation of law in obtaining the evidence
> * the significance of the method of obtaining the evidence in relation to its credibility
> * the significance of the evidence for deciding the matter
> * and the other circumstances.
Namely, considering that these documents were obtained in probably the most heinous possible violation of the person's privacy, it would not be possible for the court to admit them as evidence. That's anyway completely moot, as if it ever became publicly known that a prosecutor or police officer had read any of these documents it would be very scandalous in of itself.
Incorrect. If you are really interested, the rules of evidence are outlined in the Code of Judicial Procedure, Chapter 17. Translation to English is available here: https://finlex.fi/en/laki/kaannokset/1734/en17340004_2019081...
The relevant part here is probably the last paragraph of section 25. It concerns the rules for admitting evidence that has not been given by the person themselves in an official investigation, and which has been obtained unlawfully. It is on page 97 in the linked PDF:
> [...] the court may use also evidence that has been obtained unlawfully unless such use would:
> * endanger the conduct of fair proceedings
> * taking into consideration the nature of the matter, the seriousness of the violation of law in obtaining the evidence
> * the significance of the method of obtaining the evidence in relation to its credibility
> * the significance of the evidence for deciding the matter
> * and the other circumstances.
Namely, considering that these documents were obtained in probably the most heinous possible violation of the person's privacy, it would not be possible for the court to admit them as evidence. That's anyway completely moot, as if it ever became publicly known that a prosecutor or police officer had read any of these documents it would be very scandalous in of itself.