The U.S. Treasury Department on Thursday sanctioned an international oil smuggling network for providing support to Hizballah and the Islamic Revolutionary Guard Corps-Qods Force (IRGC-QF). The network used front companies to blend Iranian oil with Indian products to help conceal its origin and evade sanctions.

The Treasury Department said in a news release that this effort helped bring in hundreds of millions of dollars in revenue for those organizations.

“The individuals running this illicit network use a web of shell companies and fraudulent tactics including document falsification to obfuscate the origins of Iranian oil, sell it on the international market, and evade sanctions,” Under Secretary of the Treasury for Terrorism and Financial Intelligence Brian E. Nelson said in a statement. “Market participants should be vigilant of Hizballah and the IRGC-QF’s attempts to generate revenue from oil smuggling to enable their terrorist activities around the world.”

The smuggling network used storage units in the United Arab Emirates to blend the oil and created counterfeit certificates of origin and quality to transfer it for sale abroad.

According to the Treasury Department, one of the biggest culprits was Viktor Artemov, who used ships flagged in countries that are less attentive to ship tracking activity to avoid being noticed by U.S. authorities. Artemov also used his shell companies in the Marshall Islands, Mauritius and Singapore to hide the fact that he was doing business with sanctioned Iranians. Artemov also helped authorize the purchase and sale of oil tankers worth up to $30 million that were used to transport the oil. 

The sanctioned entities include a number of shipping companies and their CEOs; they have been blocked from conducting business with the United States or people in the United States. Anyone who does business with the newly sanctioned individuals and companies can be subject to secondary sanctions.