Investigations are at the core of the Commissioner’s activities. Under the Ombudsman Act the Commissioner’s main obligation is to investigate “improprieties” relating to the constitutional right to a healthy environment (subject). In his proceedings the Commissioner may find facts, make recommendations or otherwise intervene in a wide range of cases. The relevant fields of investigation (scope) is laid down in Annex I to the Rules of Investigation. Practically any person, including foreign subjects, can lodge a complaint with the Commissioner but investigations can be launched upon his own initiative too. The framework of the process of investigations is laid down in the Ombudsman Act while the detailed rules are established by the Rules of Investigation. During the investigation as well as following the conclusion of the process the Commissioner may have recourse to a broad range of measures, although typically he makes non-binding recommendations to the competent authorities or their supervisory authorities.