Wisconsin Statutes Taxation (Ch. 70 to 79) § 73.04. Hearings, witnesses

(1) Contempts.If any person unlawfully fails to obey any subpoena to appear before the department of revenue or before the tax appeals commission, or unlawfully refuses to testify, such failure or refusal shall be reported to the attorney general and the department of justice shall institute contempt proceedings against such person.

(2) Fees. Officers who serve subpoenas, and witnesses attending hearings at the instance of the department, shall receive like compensation as officers and witnesses in the circuit court. Such compensation shall be charged to the proper appropriation for the department of revenue.

(3) Special investigations. The department of revenue may appoint any employee to act for it to investigate and make report to the department upon any matter upon which the department is required to act, and such employee shall have authority to hold hearings, administer oaths, take testimony and perform all other duties necessary to bring such matter before the department for final adjudication and determination.