Oregon Revised Statutes Revenue and Taxation § 319.935

(1) The Department of Transportation may investigate a refund application submitted under ORS 319.930 and gather and compile such information related to the application as the department considers necessary to safeguard the state and prevent fraudulent practices in connection with tax refunds and tax evasion.

(2) The department may, in order to establish the validity of an application, examine the relevant records of the applicant for such purposes.

(3) If an applicant does not permit the department to examine the relevant records, the applicant waives all rights to the refund to which the application relates.