The County Council, the County Executive, the Chief Administrative Officer, the Personnel Board, the County Board of Appeals, the County Auditor and such other officers or agencies of the County as may be so empowered by ordinance of the County Council or otherwise by law shall have the power to administer oaths, to compel the attendance of witnesses and to require the production of records and other materials in connection with any investigation, inquiry or hearing authorized by this Charter or by law.