One recent operation revived a very large crude carrier Sos (IMO: 9233791), also formerly known as Assos, scrapped in 2022. Its IMO number was used by US-sanctioned VLCC, Jaya (IMO: 9410387), to smuggle Iranian oil into China earlier this year, according to Lloyd’s List analysis.

During this period, Jaya repeatedly changed its vessel name and used different Maritime Mobile Service Identity (MMSI) numbers to broadcast its position and identity.

An MMSI is a unique nine-digit number assigned to a vessel for identification and communication via radio and AIS, but it can be manually altered by crew on board.

This practice fragments the vessel’s AIS and maritime database history into multiple “ships”, making tracking harder and concealing the vessel’s true routes and port calls. Such tactics are common in “dark ship” operations, illicit oil trades and efforts to bypass port inspections.

The most recent signals showed the vessel anchoring near Dalian, China, using the name Quasar and the IMO number of the scrapped ship — a clear sign of identity fraud, as the IMO’s Global Integrated Shipping Information System lists no tanker named Quasar.

Similar tactics were observed earlier this year and last year. The previous case involved a VLCC trading as King Plus, which also used the IMO number of the scrapped EM Longevity while operating under names including Full Wood, Stellar Oracle and Young Yong.

These examples show that sanction-busting traders and vessel operators are becoming increasingly adept at these methods.

Jaya was sanctioned by the US Office of Foreign Assets Control in December 2024 for carrying Iranian oil.

Identity theft

Still operating under its original identity and IMO, Jaya was observed manipulating its AIS in the Middle East Gulf on and around March 7 to March 18. According to Madani, Jaya received a cargo via a ship-to-ship transfer from a National Iranian Tanker Company vessel during that period. Satellite imagery from PlanetLabs captured the NITC tanker loading in Kharg Island on March 11, and the STS two days later. Vortexa data shows that Jaya received nearly 2m barrels of Iranian heavy crude.

A little over a week later, the identity of Assos, which was sent for scrapping in Bangladesh three years ago, was revived, using its last known MMSI (355810000) and broadcasting its IMO number (9233791) and name, with AIS data indicating the resurrected vessel sailing south towards Malaysia in the South China sea. This continued until around April 2, 2025, when AIS coordinates placed it between the Riau Archipelago and Malaysia.

On April 8, Jaya briefly broadcast the name Quasar and the Assos IMO when it near Malaysia’s southeast coast using its own MMSI number, 306033000. Jaya’s own AIS signals — broadcasting its original IMO (9410387) — also ceased that day.

On April 11, MMSI 306662000 began broadcasting Assos’ IMO, with its coordinates placing near an oil berth at Pengerang port, Malaysia. The next day, AIS data showed it sailing to China.

By April 20, coordinates showed the vessel docked at Dongjiakou in Shandong, China, a hub for buyers of sanctioned oil from Iran, Russia and Venezuela. Satellite imagery confirmed a VLCC matching Jaya’s appearance at the site.

Afterwards, the MMSI broadcasting Assos’ identity changed several times, indicating another layer in the effort to obscure the vessel’s movements with “virtual clones”.

For several hours on April 22, MMSI 668116326 was broadcasting the Assos IMO and the name Hathor, showing its location east of Malaysia while Jaya, still using the same IMO and the name of the revived Assos, was still broadcasting its location in Dongjiakou.

On May 1, as Jaya was sailing south between Riau Archipelago and Malaysia, MMSI 620999944 began broadcasting the same IMO (9233791) as Quasar — the name briefly broadcast by Jaya’s MMSI on April 2 — at the same time that MMSI 306662000 was broadcasting as Assos. Both signals travelled along a continuous path and stopped later that day.

Three days later, MMSI 620999944 resumed broadcasting as Quasar with Assos’ IMO number (9233791).

Analysis of the positions broadcast by Quasar and satellite data indicates that between May 4 and May 9, Quasar appeared to spoof its location. During this period, its GNSS coordinates, speed and course all remained unchanged near a Malaysian port, but satellite images showed no vessel at that location.

According to Vortexa, Quasar received about 1.8m barrels of Iranian crude via an STS operation offshore Singapore with another NITC tanker.

On May 13, Quasar’s draught increased from 11 metres to 19.2 m, indicating that it had loaded cargo, after which it sailed north, arriving near Qingdao, Shandong, on May 23 and remaining there for about four days without a change in draught. 

Earlier that month, the US imposed sanctions on a third independent Chinese refinery and three port operators in Shandong’s Dongying port as part of its efforts to clamp down on Iranian oil shipments.

On May 27, Quasar departed these waters and sailed further north, arriving near Dalian in a few days, where it remains at anchor with its draught indicating it is laden, suggesting the cargo is still on board.

Satellite imagery from the European Space Agency dated May 27 suggests it is still Jaya broadcasting Assos’ IMO and using the Quasar name.

Ports in Shandong, including Dongying, and further north in Dalian, are considered major entry points for sanctioned oil flowing into China.

Amid the Trump administration’s “maximum pressure” campaign on Iran, Chinese ports are becoming more cautious, and more sanctioned and “dark fleet” tankers are resorting to disabling AIS or broadcasting false identities to conceal their movements when calling at these ports.