Oregon Revised Statutes Trade Regulations and Practices § 646.618

(1) Except as provided in ORS 646.633, when it appears to the prosecuting attorney that a person has engaged in, is engaging in, or is about to engage in any act or practice declared to be unlawful by ORS 646.607 or 646.608, the prosecuting attorney may execute in writing and cause to be served an investigative demand upon any person who is believed to have information, documentary material or physical evidence relevant to the alleged or suspected violation. The investigative demand shall require such person, under oath or otherwise, to appear and testify, to answer written interrogatories, or to produce relevant documentary material or physical evidence for examination, at such reasonable time and place as may be stated in the investigative demand, or to do any of the foregoing, concerning conduct of any trade or commerce which is the subject matter of the investigation.

(2) At any time before the return date specified in an investigative demand, or within 20 days after the demand has been served, whichever period is shorter, a petition to extend the return date, or to modify or set aside the demand, stating good cause including privileged material, may be filed in the appropriate court.