Abstract
The contribution is devoted to the issue of the overlap of criminal law in case of breach of fiduciary duties. First, in the theoretical part, it deals with the general definition of the term fiduciary, then characterizes the basics of fiduciary relationships and their content.
In the practical part, it deals with some inverventions of criminal law into breach of fiduciary duties. This topic requires constant attention, as criminal legislation in this area is not completely perfect.
I consider the key problems to be the absence of the legal definition of the concept of the due diligence as the basis of proper care, and for futuro I also mention a possible problem that may arise when defining a criminal offense using a blanket substance of crime and a situation where there will be an expert discussion and a court decision, which may result in uncertainty regarding criminal liability if not a violation of the nullum crimen sine lege principle.