One of the biggest money-spinners for Islamic State terrorists is transporting illegal drugs from Afghanistan to Europe through Turkey and the Balkans, according to the head of Russia’s federal anti-drug agency FKSN.

“ISIS fighters are controlling certain territory,” Viktor Ivanov was quoted as saying by TASS. “Now it is targeted by the Russian Air Force, but until recently the terrorists enjoyed great freedom there. Trafficking illegal drugs was one of the major sources of their income.”

Ivanov added that so far the heroin transported to the European Union via Turkey and the Balkans yields Islamic State (IS, previously ISIS/ISIL) about $150 billion for distribution to members of the criminal chain. “This money is getting into the criminal turnover and destabilizes the situation in the transit countries. Turkey is exactly such a country,” Ivanov told reporters.

READ MORE: ISIS economy based on illegal drug trade - Russian anti-drug chief

In July, Russia’s top drug enforcer spoke at an international anti-trafficking conference in Gambia and said that the $500 billion annual income from illegal drug trade was the financial and organizational basis for new terrorist organizations, such as Boko Haram, Islamic State and others. “Illegal drugs are a kind of gold and foreign currency reserves for quasi-state groups,” he said.

In March, Ivanov said in a press interview that IS made up to $1 billion annually from Afghan heroin trafficked through its territory. He predicted another record-high poppy harvest in the terrorist-controlled lands, and urged countries to raise the issue of fighting the IS drugs trade at the highest international level, including at the UN, saying it represents a global security threat.