The Mayor may, without notice, cause the affairs of any department or the conduct of any officer or employee to be examined. Any person or persons appointed by the Mayor to examine the affairs of any department or conduct of any officer or employee, shall have the same power to compel the attendance of witnesses, and the production of books and papers and other evidence and to cause witnesses to be punished for contempt, as is conferred upon the Council or a committee thereof by this Charter or by law.