The Customs Department and the RBI are sharing data to plug gaps in the export-import trade that leads to situations where remittances are made from importers’ accounts even if goods are not been shipped from the selling country.
Banks usually ask for export and import documents — which include bill of lading and customs clearance — before they release funds.While India was generating a unique number for exports, it was not generating a unique number based on the shipping bill for imports.

Source - http://www.thehindubusinessline.com