The social nature of human beings pushes them for social interaction and each human being has their own interests, which may not always coincide with the interests of other individuals. Therefore, a state’s high priority task is to ensure that every human being and the whole society is protected by the state from unlawful acts. The state is obliged to take legal means to disclose the criminal acts committed by the individuals, and limitation of human rights and fundamental freedoms is inevitable. It means that law enforcement agencies can enter a person’s private life protected by international and national law. In given situations, a form of competition arises between the two legal values protected by the law: the right of the people to be secure in their persons and the right of person to privacy and dilemma how to tackle in case of collision of two mentioned values during pre-trial investigation. Based on international standards formulated by European Court of Human Rights, a person’s right to privacy can be limited in some cases if such restrictions procedures, in details, are prescribed by law. Mandatory requirements for law restricting a person’s privacy are: accessibility (publicly accessible for everyone who wish to introduce); targeting legal objectives; possibility to protect a person‘s rights from illegal actions; foreseeability; necessity in the democratic society for the prevention of disorder or crime; state‘s interference into a person‘s privacy must fit pressing social need. The states (signatories of 1950 European Convention on Human Rights) enjoy a certain but not unlimited margin of appreciation in the matter of the imposition of restrictions on a person‘s right to privacy. [...]