43 CFR § 17.333 - Investigation.
(a) Informal investigation.
(1) DOI will investigate complaints that are unresolved after mediation or are reopened because of a violation of a mediation agreement.
(2) As part of the initial investigation, DOI will use informal fact finding methods, including joint or separate discussions with the complainant and recipient to establish the facts, and, if possible, settle the complaint on terms that are mutually agreeable to the parties. DOI may seek the assistance of any involved State agency.
(b) Formal investigation. If DOI cannot resolve the complaint through informal means, it will develop formal findings through further investigation of the complaint. If the investigation indicates a violation of these regulations, DOI will attempt to obtain voluntary compliance. If DOI cannot obtain voluntary compliance, it will begin enforcement as described in § 17.335.