All persons served with an investigative demand, other than those persons whose conduct or practices are being investigated, or any officer, director, or person in the employment of the person under investigation, shall be paid the same fees and mileage as paid witnesses in the courts of this state. No person shall be excused from attending the inquiry pursuant to the mandate of an investigative demand or from giving testimony or from producing documentary material or from being required to answer questions on the ground of failure to tender or pay a witness fee or mileage unless demand therefor is made at the time testimony is about to be taken and unless payment thereof is not thereupon made.
110 R.I. Code R. 110-RICR-30-00-1.7