The accused had prepared false documents, like purchase orders, invoices and procurement papers, and used them for filing shipping bills in Petrapole land customs station.
The forged shipping bills were processed for exports on paper only without presenting actual goods and vehicles supposed to be carrying the goods, the official said.
Investigation revealed that the syndicate provided false vehicle numbers on the shipping documents and had forged the stamp of Bangladesh customs to show that consignment crossed the border.
"Import Export Code of 10 such exporting firms were used in preparing 51 fraudulent shipping bills, wherein, goods like pan masala, two-wheeler and three-wheeler parts, motor parts and items eligible for higher GST refunds worth Rs 24 crore were shown to have been exported," a DRI official said.
It involved around Rs 12 crore export benefits, the official added.
The agency had arrested three members of the syndicate in December 2018 who got the fraud executed through different Bongaon-based crooks.
The customs broker who had allowed his stamps to be used in the fraud was also arrested in January 2019.
Apart from these syndicate members, five customs officers have also come under the scanner for facilitating the fraud.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)