Sweden releases boarded Russian freighter after customs inspection

This week, Swedish authorities detained the Russian cargo vessel Adler(IMO 9179854, MMSI 273414440)   after it anchored in Swedish waters due to a mechanical failure – a common risk across the aging and isolated shadow fleet. According to Windward data, Adler is a Ro-Ro Cargo Ship built in 1998 (27 years old) has been designated on the OFAC SDN list since May 2022 and is owned and managed by entities explicitly sanctioned for supporting Russia’s war effort. The vessel is owned by M Leasing LLC and managed by MG-Flot LLC, both sanctioned by the EU, UK, UN, and U.S. authorities. MG-Flot has also been sanctioned under the EU’s Iran sanctions regime for its role in supporting Russia.

"They are not allowed to sail further without the go-ahead from the prosecutor," Swedish Customs Press Secretary Martin Hoglund told the regional broadcaster SVT.  

Swedish Customs then boarded the vessel 

It is noteworthy that the cargo ship Adler suffered engine failure and anchored off Sweden's west coast on Dec. 20 Whereas  Swedish Customs then boarded the vessel and carried out an inspection in cooperation with the Coast Guard. The case has now been forwarded to Prosecutor Henrik Soderman at Sweden's National Unit for International Organized Crime.

The Adler has previously been used to transport Russian weapons and its owner, M Leasing LLC, is sanctioned by the U.S. and EU.  The company was sanctioned for using its ships to carry North Korean ammunition to Russia for use in the war against Ukraine.

In addition to the Adler being on a European Union sanctions list, the vessel and its owners M Leasing LLC are both subject to U.S. sanctions, suspected of involvement in weapons transport, according to Open Sanctions, a database of sanctioned companies and individuals, persons of interest and government watchlists

The Adler’s path from Russia's Bronka Port

The Adler’s path from Russia’s Bronka Port to being anchored and detained off Sweden’s western coast.
Operationally, Adler exhibits multiple high-risk indicators. She sailing under the Russian flag, has conducted seven port calls to Russia, most recently at Bronka Port on December 15, 2025, and operates within a sanctioned ownership and management network. Its detention was not a random incident, but the result of a degrading fleet forced into jurisdiction by mechanical failure.

The customs service declined to say what cargo the Adler, which left St Petersburg on December 15 for an unknown destination, had been carrying. LSEG tracking data showed the ship travelling north up the west coast of Sweden according to Reuters

Global Maritime Implications

Taken together, these developments point to a fundamental change in maritime risk. Enforcement is increasingly behavior-driven rather than list-based, exposing shadow fleet operations wherever they operate. As pressure increases, GNSS manipulation, false narratives at sea, and complex ownership structures are likely to intensify.

According to ship-tracking service Marine Traffic, the Adler is a 126m-long, roll-on, roll-off container carrier. It is anchored off Hoganas in south-west Sweden.  The ship had left the Russian port of St Petersburg on Dec 15, but he said customs did not have any information about its destination. REUTERS

 U.S. Coast Guard boarded the tanker Centuries

It is noteworthy that When the U.S. Coast Guard boarded the tanker Centuries (IMO 9206310) in international waters off Venezuela, its AIS signal placed it near Aruba and Curaçao. Windward data confirms the vessel was operating far closer to the Venezuelan coast, a familiar pattern seen across dark fleet activity.

Unlike the Skipper, seized the previous week, Centuries was not on any U.S. sanctions list. This is the first confirmed case of a non-designated tanker being seized under the new enforcement posture. The decision appears to have been driven not by designation, but by behavior.

Windward’s Maritime AI™ platform 

Windward’s Maritime AI™ platform had flagged Centuries as high risk since June 2024, 2025, due to repeated GNSS manipulation, identity and location tampering, irregular business structure, and multiple ship-to-ship transfers with a sanctioned tanker linked to the Russian regime. The vessel’s opaque ownership structure, Hong Kong-based management, and rapidly shifting fleet flags further align it with known dark fleet typologies.

These seizures signal a material shift. The blockade around Venezuela is no longer limited to sanctioned vessels – it now extends to tankers that either carry sanctioned oil or exhibit dark fleet behavior. according to WINWARD 

Interception of a third vessel, Bella 1 

That shift became clearer with yesterday’s interception of a third vessel, Bella 1 (IMO 9230880). Unlike Centuries, Bella 1 is fully designated by OFAC under the SDGT and Iran sanctions programs, and is controlled by the sanctioned Turkish company Louis Marine Shipholding. The Guyana-flagged crude tanker was intercepted north of the Lesser Antilles while still en route to Venezuela, before reaching the loading zone. This vessel has been flagged as high risk by Windward’s Maritime AI™ platform since April 2023 as a result of multiple smuggling risk indicators, such as dark activities, deviations from normal shipping patterns, multiple identity changes, and uneconomical behavior. 

A tanker blockade,

The seizure of Centuries and Bella 1, and Sweden’s detention of the sanctioned cargo vessel Adler, crystallizes the shift. A blockade that began as a sanctions tool is rapidly becoming a tanker blockade, reinforced by growing political calls to physically seize shadow fleet vessels, with global implications for energy flows, maritime security, and escalation dynamics.

Related : U.S. Coast Guard seizes Panama-registered Oil tanker moving sanctioned of Coast Venezuelan

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