The board or a referee, if it or he deem it necessary, may, of its or his own motion, either before, during or after any hearing, make an investigation of the facts set forth in the petition or answer. The board or referee with the consent of the board, may appoint one or more impartial physicians or surgeons to examine the claimant and report thereon, or he may employ the services of such other experts as shall appear necessary to ascertain the facts. The report of any physician, surgeon, or expert appointed by the board or by a referee shall be filed with the board or referee, as the case may be, and shall be a part of the record and open to inspection as such.

The board shall fix the compensation of such physicians, surgeons, and experts, which, when so fixed, shall be paid out of the sum appropriated to the Department of Labor and Industry.

The sum of fifty thousand dollars ($50,000) is hereby appropriated to the Department of Labor and Industry for compensation payable by the Commonwealth under the provisions of this section for the biennium one thousand nine hundred fifty-five-one thousand nine hundred fifty-seven.