Customs valuation integrity requires voluntary, corroborated evidence before enhancing declared import value or imposing penalties.
Enhancement of import value and penalties for alleged under invoicing were unsupported where export declarations were unattested photocopies later rectified by the supplier, key statements under Section 108 were retracted and lacked corroboration, and contemporaneous import comparisons were dismissed without contrary evidence; therefore, voluntariness and corroborative evidence are required before altering declared value or imposing penalties.