Greek authorities intercepted a huge quantity of synthetic opiates that arrived in the country's busy Piraeus port last week from New Delhi, reportedly disguised and labeled as household linen.

The shipment of opiates — specifically 26 million tablets containing the prescription painkiller Tramadol — were bound for Libyan shores, and authorities are investigating whether the Islamic State had anything to do with it.

The US Drug Enforcement Agency (DEA) reportedly tipped off the Narcotics and Arms Division of Greece's Financial Crimes Unit (SDOE) about the haul — with an estimated street value of $13 million — due to arrive from India.

Loukas Danabasis, director of the SDOE, told Reuters that the companies involved in this trafficking incident "had been previously involved in such transfers." The receiving company in Libya, Danabasis added, "is characterized as being suspect of having relations with the Islamic State."

VICE News was unable to verify if the recent bust was being investigated for links to the Islamic State.

However, Russell Baer from the DEA was able to confirm that large quantities of Tramadol are frequently trafficked between New Delhi and Libya, and that the North African country has emerged as a "significant hub for Tramadol trafficking" in the region over recent years.

Since 2015, Baer says, law enforcement officials from Dubai, Egypt, Malta, Singapore, and Spain have seized nearly 200 million Tramadol tablets, all of which were bound for Tobruk, a Libyan port city on the Mediterranean near the Egyptian border.

According to the United Nations Office on Drugs and Crime, there are loopholes in the laws that regulate India's vast pharmaceutical industry, making it possible to easily divert drugs like Tramadol on a large scale from legitimate manufacturers to the black market.

Baer says that Tramadol is a popular drug in Egypt, the Middle East, and in West Africa because it's potent, available and inexpensive. Drug traffickers are working to ensure that their shipments of Tramadol are large enough to satisfy the region's hunger for the prescription painkiller.

Growing demand for the drug, particularly in unstable regions across the Middle East and North Africa (MENA) "poses potentially significant security threat to the region" according to Baer, who says there is an "increasing concern that insurgents and foreign terrorist organizations may further exploit the drug trade to finance their operations."

Libya has been engulfed in lawlessness and chaos since the fall of former dictator Muhammar Qaddafi in 2011. Tripoli, the county's capital, and LIbya's second largest city Benghazi are dominated by Islamist rebels, including IS.

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IS militants have been suspected of financing some of their operations through drug trafficking in the past. When Syria's Aleppo fell to IS in January 2014, militants reportedly came into possession of a pharmaceutical plant capable of manufacturing the amphetamine Captagon. The drug is said to be popular among militants because its speed-like quality allows them to fight for longer without getting tired.

The DEA's Russell Baer mentioned Captagon in his email to VICE News, noting that although it is banned in most countries since the mid-1980s, it continues to be manufactured and sold in the Middle East and North Africa. It's profitable, too – sold for pennies on the dollar and usually fetching about $20 per tablet on the street.