In the year of the US military’s dramatic seizure of the Indian Ocean, an oil tanker known as the MT Tiffany made several trips between the coasts of Iran and Malaysia to waters about 60 miles from Singapore’s skyscrapers.
According to marine traffic data reviewed by CNN, during these voyages, it often hides in a small area before dropping anchor and turning off its mandatory Automatic Identification System (AIS).
After some time – sometimes hours, sometimes days – the ship will reappear on the AIS.
Tuesday’s seizure of the MT Tiffany — and 1.9 million barrels of Iranian oil, U.S. officials said — pushed the war with Iran thousands of miles from the Persian Gulf into Indo-Pacific waters.
It has also put a spotlight on this patch of Malaysian waters, about half the size of Rhode Island, which experts and CNN analysis say serves as a floating gas station for Iran, used by its shadow fleet to trade and store oil, a war-torn regime desperately in need of cash.
Synthetic Aperture Radar (SAR) satellite imagery shows ships within the eastern outer harbor limits off the coast of Malaysia on April 18, 2026. – Sentinel 1/European Space Agency
Although not officially defined, this area is commonly known as the Eastern Outer Port Limits (EOPL) anchorage. It is located near the eastern entrance to the Singapore Strait, one of the world’s busiest shipping lanes, about 43 miles off the coast of Peninsular Malaysia, in the country’s Exclusive Economic Zone (EEZ). This is most visible in satellite imagery where, at times, hundreds of ships can be seen moving through the area.
MT Tifani can also be identified by its IMO number: 9273337. As assigned by the International Maritime Organization, the number cannot be changed regardless of ownership or flag.
On one occasion last August, another ship, the Macho Queen (IMO: 9238868), was seen offloading an unspecified cargo within the area, according to satellite images reviewed by CNN. After the transfer, Macho Queen briefly turned on her AIS and began traveling northeast toward China before turning off her tracker again after the US approved it for smuggling Iranian oil to China.
Satellite imagery appears to show MT Tiffany making a ship-to-ship transfer with Macho Rani off the east coast of Malaysia in August 2025. – European Space Agency
A second oil tanker boarded and seized by the U.S. on Thursday, the MT Majestic X, also made multiple trips between the Middle East and the Singapore Strait toward the EOPL, according to Marine traffic data.
EOPL is a hotspot for the shadow fleet because of its convenient location and the permissive attitude of nearby officials, said Farzin Nadimi, a senior fellow at the Washington Institute think tank who specializes in Iran.
“It’s a very convenient location for hide-and-seek activities,” Nadimi said. “Malaysian authorities basically look elsewhere.”
At least 679 ship-to-ship transfers took place at the EOPL in 2025, 471 in 2024 and 280 in 2023, according to satellite data compiled by the non-profit United Against Nuclear Iran (UANI). These numbers underestimate the real picture because the satellite does not pass every day and cannot detect ships in bad weather.
CNN has reached out to the Malaysian government for comment.
Last July, Malaysia vowed to enforce against illegal ship-to-ship transfers in its waters, with Foreign Minister Mohd Hasan admitting the issue was a “thorn in our side”, state media Bernama reported.
Under the new rules, any vessel making an unauthorized transfer will be detained, Mohammed said, according to Bernama.
“We no longer want to be accused of being a country that supports such activities.”
Iran is one of the world’s top oil producers, exporting an average of 1.69 million barrels per day in 2025, according to trade data and analytics company Kpler. According to the US government, about 90 percent of its oil goes to China. China has not embargoed Iranian crude oil and it opposes sanctions on Iranian oil.
Due to widespread sanctions, Iran relies on a fleet of aging tankers with opaque records and spotty insurance to move crude around the world.
US troops aboard the M/T Tiffany on April 21, 2026. – @DeptofWar/X
Its shadow fleet consists of very large crude carriers (VLCCs), according to energy data firm Vortexa – giant tankers like the MT Tiffany that can hold up to 2 million barrels of oil.
Most of its accepted oil sells at about a $10 discount to global benchmark Brent crude, which has risen above $100 a barrel since the war began, meaning each ship-to-ship transfer nets tens of millions of dollars in revenue for Iran’s regime.
Activity at the EOPL has continued since the US and Israel launched a war against Iran in late February by blocking the flow of oil from the Middle East. UANI tracked at least 250 ship-to-ship transfers at the EOPL anchorage between January and April 21 this year.
Iran’s use of the region allowed it to maintain a steady flow of exports during the war, bankrolling the regime even as the world faced severe oil shortages.
“It’s essential to Iran’s business model,” said Charlie Brown, senior adviser to UANI, focusing on Iran’s shadow fleet.
How the ‘Cargo Laundering Business’ Works
Ship-to-ship transfers are a regular part of legitimate long-distance shipping, used to increase efficiency and avoid ports.
Large oil tankers often offload their cargo onto smaller ships because their draft is too deep to enter most ports. But because these maneuvers carry safety and environmental risks, they are highly regulated and must be carried out in approved areas, requiring full documentation and notification of coastal authorities.
Shadow fleets use ship-to-ship transfers, even when logically unnecessary, to obscure the origin of the oil they carry. They often operate them under the cover of night, turning off or spoofing their AIS, making it difficult for authorities to detect them.
Broadly speaking, Iran’s shadow oil trade follows a similar pattern, with two ships helping to deliver Iranian crude to China.
The first set of vessels mainly pick up oil from Iran’s primary export facility, Kharg Island, and cross the Indian Ocean via the Straits of Malacca and Singapore, before anchoring in Malaysia.
Marine traffic data shows MT Tiffany made multiple trips between the Persian Gulf and EOPL from April 2025 until its capture by US forces in April 2026. – Maritime transport
Ships from the second set then receive the oil by ship-to-ship transfer and take it to China, mainly to “teapot” refineries in Shandong province, which are known for buying approved crude.
China does not officially declare Iranian crude imports and often hides the origin of Malaysian oil, said Ying Kang Lah, crude oil market analyst at Kepler.
CNN has reached out to China’s foreign ministry for comment. Earlier this month, a ministry spokesman said Beijing “opposes unilateral sanctions that have no basis in international law” when asked about the US assessment that China would stop buying Iranian oil.
Most ships transporting oil from Iran to Asia have been blacklisted by the US, while most ships picking up oil and taking it to China have not yet been sanctioned, said Brown, a senior adviser to UANI.
Shadow fleets also forge documents and fly false flags or “flags of convenience”, frequently changing their registration and misrepresenting their cargo to fool authorities.
“They create a new story for a new cargo and a new ship,” said Nadimi of the Washington Institute, and crews sometimes go so far as to paint a new name or flag on the ship. “It’s a cargo laundering business.”
The nefarious activities at EOPL have long been an open secret in the shipping industry. Brown estimates that about 95% of Iranian or Russian oil is being smuggled to China on ships transferring cargo to the region.
Strategic stockpile near China
The EOPL has also served as a kind of oil storage site for Iran, helping prevent any disruption to shipping traffic in the Persian Gulf, Nadimi said.
“There is a risk of provoking hostilities in the Strait of Hormuz in the Gulf region, so they (Iran) prefer to move as much cargo, crude oil, as close to their customers.”
This satellite image shows Iran’s Kharg Island on March 11, 2026, before the US strike on the island. – Airbus
Iran stored a record 191 million barrels at sea in February, the largest in East Asia, according to Kepler.
This floating strategic reserve has allowed Tehran to maintain high exports, shipping an average of 1.1 million barrels per day to China, even as the US and Israel hit the country with strikes throughout March, according to UANI. While its export numbers dipped from normal, the rise in oil prices helped the regime offset the economic blow.
MT Tiffany may have been on her way to offload cargo at EOPL when it was boarded by US forces.
The recently docked tanker ship MT Tiffany is seen docked at the Kharg Island terminal in Iran on April 6, 2026. – Airbus
In the month since its capture, the ship has circled the Strait of Hormuz and the Persian Gulf, according to marine traffic data. Although the tanker’s AIS was off, CNN was able to locate the tanker docked off Iran’s Kharg Island in satellite imagery taken on April 6.
The tanker reappeared on AIS on April 10, when it was seen traveling southeast in the Gulf of Oman. Marine traffic data showed it heading towards Singapore.
On April 21, after crossing Sri Lanka, the tanker made an abrupt course change — first a sharp 90-degree turn to the south, then another sharp 90-degree turn to the east. Shortly after the ship made these course changes, the US announced its capture.
In a video posted by the Department of Defense, US troops can be seen above as helicopters circle MT Tiffany.
MT Tiffany has been roaming the area ever since.
CNN’s Steven Jiang contributed reporting.
Create an account at CNN.com for more CNN news and newsletters
