(1) Notwithstanding anything contained in this Act, but without prejudice to the provisions contained in
section 46 —
(a) where the proper officer is satisfied that an importer or exporter is unable to produce any document or
furnish any information necessary for the assessment of duty on the imported goods or the export
goods, as the case may be; or
(b) where the proper officer deems it necessary to subject any imported goods or export goods to any
chemical or other test for the purpose of assessment of duty thereon; or
(c) where the importer or the exporter has produced all the necessary documents and furnished full
information for the assessment of duty but the proper officer deems it necessary to make further
enquiry for assessing the duty, the proper officer may direct that the duty leviable on such goods may,
pending the production of such documents or furnishing of such information or completion of such test
or enquiry, be assessed provisionally, if the importer or the exporter, as the case may be, furnishes
such security as the proper officer deems fit for the payment of the deficiency, if any, between the duty
finally assessed and the duty provisionally assessed.