A multi-jurisdiction grand jury has statewide subpoena power and, through special counsel, may subpoena persons to appear before it to testify and may subpoena the production of evidence, with or without the custodian of records at the election of special counsel, in the form of specified records, papers, documents, or other tangible things. Such subpoenas shall be returnable for a specific meeting of the multi-jurisdiction grand jury. Mileage and such other reasonable expenses as are approved by the presiding judge shall be paid such persons from funds appropriated for such purpose. A witness before a multi-jurisdiction grand jury shall be entitled to the presence of counsel in the grand jury room, but he may not participate in the proceedings. The foreman shall administer the oath required by law for witnesses.