Assignment of proper officer functions to Customs Audit officers extends statutory authority under sections governing custody and release. The Central Board assigns functions of the proper officer under the Customs Act to specified Customs Audit officers-Principal Commissioners or Commissioners (Audit), Additional or Joint Commissioners (Audit), and Deputy or Assistant Commissioners (Audit)-for the purposes of section 17 and section 28 of the Act; the notification was later superseded by a subsequent notification.