1. Conduct investigations relative to the complaint or matter being investigated, and he shall have at all times unimpeded access to all buildings, yards, warehouses, storage and transportation facilities in which any farm products are kept, stored, handled, or transported;

2. Administer oaths and take testimony, and issue subpoenas requiring the attendance of witnesses before him, together with all books, memoranda, papers, and other documents, articles or instruments; and

3. Compel the disclosure by witnesses of all facts known to them relative to the matters under investigation.