This work provides a critical analysis of the inquiry and intervention rights of investigation committees investigating in the private sphere based on references to criminal procedure regulations in article 44 section 2 sentence 1 of the Basic Law of the Federal Republic of Germany (Grundgesetz - GG) and the law of parliamentary investigation committees (parlamentarische Untersuchungsausschussgesetz - PUAG). This analysis aims to define the extent and limitations of the inquiry and intervention rights and to provide a practice relevant presentation of the inquiry and intervention rights of investigation committees investigating in the private sphere.