Section 5(3)(b) in The Customs Tariff (Determination of Origin of Products under the Duty Free Tariff Preference Scheme for Least Developed Countries) Rules, 2015
(b)for materials, the origin of which cannot be determined, the earliest price ascertained to have been paid in the territory of the exporting beneficiary country where the working or processing takes place, in accordance with the Agreement on Customs Valuation.