The council shall have power to compel the attendance of witnesses and the production of papers relating to any subject under consideration in which the interest of the city is involved, and shall have power to call on the proper officer of the city, or of the county in which such city is located, to execute such process. The officer making such service shall be entitled to receive therefor such fees as are allowed by law for similar service, to be paid by the city. The president of the council, or president pro tem, shall have power to administer oaths to witnesses.