Oregon Revised Statutes Labor and Employment; Unlawful Discrimination § 663.270

(1) The Employment Relations Board or its duly authorized agents at all reasonable times shall have access to, for the purpose of examination, and the right to copy, any evidence of a person being investigated or proceeded against that relates to any matter under investigation or in question. The board, upon application of a party to such proceedings, forthwith shall issue to that party subpoenas requiring the attendance and testimony of witnesses or the production of any evidence in the proceeding or investigation requested in the application.

(2) Within five days after the service of a subpoena on a person requiring the production of any evidence in possession or under the control of the person, the board on petition of that person shall revoke the subpoena if in its opinion the evidence whose production is required does not relate to any matter under investigation, or any matter in question in the proceedings, or if in its opinion the subpoena does not describe with sufficient particularity the evidence whose production is required.

(3) The board or its agent designated by it for such purposes, may administer oaths and affirmations, examine witnesses and receive evidence. Attendance of witnesses and the production of such evidence may be required at any designated place of hearing.