Surge of Iranian Oil Tankers Near Malaysia Amid Rising Sanctions Pressure

By Serene Cheong and Alex Longley

March 27,2025 (Bloomberg) – A cluster of nearly a dozen US-sanctioned tankers is currently anchored off the coast of Malaysia,loaded with Iranian crude oil. Some of these vessels have been lingering in this oil-transfer hub for over a month, hinting at potential delays in logistics for the sensitive trade route to China.

According to ship-tracking data from Bloomberg, at least 11 tankers carrying Iranian oil are either stationary or moving at sluggish speeds this week. Together, they hold around 17 million barrels and are gathered in an area east of the Malaysian peninsula—a well-known location for ship-to-ship transfers involving Iranian crude.

In recent months, the flow of Iran’s oil from key export points like Kharg Island to cargo-switching locations such as Malaysia has come under increased scrutiny. This follows a ramp-up in US sanctions aimed at Tehran that target ships and entities supporting its regime.

Data from OilX indicates that the number of Iranian oil-laden vessels idling near Malaysia and Singapore has reached its highest level sence august. Shipbrokers and analysts note that while this flotilla appears larger than usual,accurately assessing how many ships are waiting is tricky since many turn off thier digital transponders to conceal their movements.

The trend shows more vessels have been idling with Iranian crude over the past week and two weeks prior. However, these figures may change as more elusive transfers become apparent.

It remains uncertain whether these tankers are poised for ship-to-ship transfers or simply biding time until private Chinese refineries express interest in purchasing their cargoes. The process of transferring cargoes at sea is becoming increasingly complex due to a dwindling fleet of unsanctioned tankers available for transporting Iranian crude.

Those involved in Iran’s supply chain—ranging from shipowners to port operators—are on high alert following Washington’s latest sanctions against a private teapot refiner along with additional measures targeting storage facilities and tankers.

As reported by late February data, over two-thirds of the tankers that transported Iranian crude last year faced blacklisting—a growth linked to slower offshore transfer rates prompting some vessels to alter their names or flags under which they operate. Despite these efforts by the US Goverment aiming to disrupt trade between Iran and China, it seems unlikely they will wholly halt it. Iran still possesses spare shipping capacity; Tankertrackers.com Inc., which utilizes satellite imagery among other tools for tracking shipments, reports that more than 20 empty tankers remain anchored near Kharg Island’s loading terminal.