Section 43. In the discharge of the duties prescribed by this chapter, the commissioner and the members of the board of review and of the state advisory council, or the duly authorized representative of any of them, shall have the power to administer oaths, take depositions, certify to official acts, and require by summons the attendance of witnesses and the production of books, papers, documents and records. Witnesses so summoned shall be paid for attendance and travel the same fees as witnesses in civil actions before the courts. Such fees shall be paid from the employment security administration account. In case of refusal to obey a subpoena issued to any person under authority of this chapter, any court of the commonwealth, within the jurisdiction of which the inquiry is carried on or the person so refusing to obey is found or resides or transacts business, may, upon application by the commissioner or his duly authorized representative or the board of review, issue to such person an order requiring him to appear before the commissioner, or his duly authorized representative or the board of review, as the case may be, to produce evidence if so ordered or to give testimony touching the matter under investigation or in question; and any failure to obey such order of the court may be punished by said court as a contempt thereof. No person shall be excused from giving testimony, or from producing any book, record, document or other paper, pertinent to the matter in question, in any investigation or inquiry by, or upon any hearing before, the commissioner or the board of review or the duly authorized representative of the commissioner or said board, when ordered to do so by the commissioner, or said board, or such representative, respectively, upon the ground that the testimony or the book, record, document or other paper required of him may tend to incriminate him or subject him to a penalty or forfeiture; but no person shall be prosecuted, punished or subject to any penalty or forfeiture for or on account of any act, transaction, matter or thing concerning which, after claiming his privilege, he shall by order have testified or produced documentary evidence, except for perjury committed in giving such testimony or forgery committed by him in such documentary evidence.