In any hearing, investigation or proceeding conducted by or before the commission or commissioner, the evidence of witnesses and the production of documentary evidence may be required at any designated place of hearing and summons may be issued therefor by the commissioner or any member of the commission. In case of disobedience to a summons or other process so issued, the commissioner, a member of the commission or any party to the proceedings may invoke the aid of any circuit court in requiring the evidence and testimony of witnesses and the production of papers, books and documents. And upon proper showing, such court shall issue an order requiring such persons to appear before the commissioner or commission, as the case may be, and produce all books and papers and give evidence touching the matter in question. Any person failing to obey such order may be punished by such court as for contempt. A claim that any such testimony or evidence may tend to incriminate the person giving the same shall not excuse such witness from testifying, but such witness shall not be prosecuted for any offense concerning which he is compelled hereunder to testify.
