In conducting the inquiries and investigations authorized by Alaska Stat. § 27.05.010 – 27.05.070, no officer or employee of the department may have a personal or private interest in a mine or the products of a mine under investigation or accept employment from a private party for services in the examination of private mineral property. Nothing in this section prevents employment by the department, in a consulting capacity or in the investigation of special subjects, of an engineer or other expert whose principal professional practice is not employment by the department.