Based on the conducted research the authors concluded that there are regulatory legal acts regulating the issues of interaction between the investigator and the body of inquiry, which in addition to the criminal procedural law include other laws and by-laws, in particular, the federal laws “On operative-investigative activity”, “On the police”, departmental orders and instructions. It is noted that the existing disputes about the legality, procedure, types and subjects of interaction, about the procedural nature and evidential significance of information obtained from interaction, about the methods of its registration demonstrate the imperfection of the current regulatory framework in this area, which prevents its effective enforcement. The article indicates that the gaps in legislation in some of the most significant areas of intervention in the system of the Ministry of Internal Affairs have been filled through regulatory legal acts issued both at the federal level of the department and the level of territorial internal affairs bodies (in the form of orders, decrees, instructions and etc.), which certainly allowed to solve a number of practical problems. The authors of the publication make proposals for improving the legislative regulation of the procedural status of the body of inquiry as a participant in a criminal process.