(a) An inquisition taken under this chapter must be returned by the coroner forthwith, together with the written statement under oath taken by him on the preliminary investigation, to the clerk of the circuit court of the county.
(b) The coroner must also require all the material witnesses to enter into an undertaking to appear at the circuit court, if in session, or, if not, at the next session thereof; he may require surety to such undertaking and, on the failure of a witness to enter therein, may commit him until he enters into the same.