Audit powers expanded to permit on site or office audits of importers, exporters and related persons, affecting customs assessments. The new provision authorises the proper officer to audit assessments of imported or export goods or of any auditee either in the officer's office or at the auditee's premises as prescribed, and defines auditee to include importers, exporters, approved custodians, warehouse licensees and any person directly or indirectly engaged in clearing, forwarding, stocking, carrying, selling or purchasing imported, export or dutiable goods.