The Revenue Department has alerted the customs commissioners about several importers defrauding the government by claiming duty refunds on forged documents and transactions.

The Central Board of Excise and Customs has unearthed fraudulent transactions and documents in case of timber importers claiming four per cent Special Additional Duty (SAD). It suspects that the modus-operandi of the revenue theft is widespread.

"These importers are defrauding the government revenue by resorting to the modus operandi of submitting the forged documents for claiming refund fraudulently," the department said in its letters to Chief Commissioners of different ports.

The communication said the fraud may have all-India ramifications and is not limited to a few cases.

"All field formations are directed to be alert and vigilant to ensure that unscrupulous importers do not avail fraudulent refunds of four per cent Special Additional Duty...," it said.

However, the communication did not name specific importers resorting to the "fraudulent" activities.