The commission shall, either as a commission or by any of its members, or by designated employees, subpoena witnesses, take testimony, administer oaths to any witness in any proceeding or examination instituted before or conducted by it with reference to any matter within its jurisdiction hereunder. In all hearings or proceedings before the commission or its designated employees, the evidence of witnesses and the production of documentary evidence may be required at any designated place of hearing within the state; and in the case of disobedience to a subpoena or other process, the commission or any party to the proceedings before the commission may invoke the aid of any circuit court in the state in requiring the evidence and testimony of witnesses and the production of papers, books, and documents. And such court, in case of refusal to obey this subpoena issued to any person or other witness, shall issue an order requiring such person or other witness to appear before the commission or designated employees and produce books and papers, if so ordered, and give evidence touching the matter in question. Any failure to obey such order of the court may be punished by such court as contempt thereof. A claim that such testimonial evidence may intend to incriminate the witness giving the same shall not excuse any witness from testifying, but such witness shall not be prosecuted for any offense concerning which he is compelled hereunder to testify.