PARIS — The Chinese captain of a suspected shadow fleet tanker was sentenced in absentia to one year in prison by a French court on Monday.

The case underscores Paris and other European capitals’ mounting efforts to crack down on Russia’s covert network of mostly aging oil tankers used to circumvent sanctions imposed after Moscow’s invasion of Ukraine.

Zhangjie Chen, 39, was convicted of failing to comply with authorities after French special forces boarded the Boracay, a vessel found sailing without a flag in international waters off the coast of Saint-Nazaire last September. According to the prosecutor, the ship departed the Russia’s Baltic Sea port of Primorsk and was carrying approximately $100 million in Russian oil, as well as two Russian citizens who the captain identified as “security agents.”

After sentencing the captain to the maximum penalty of one year in prison and a fine of €150,000, the court issued a warrant for his arrest. Chen was at sea at the time of his trial in February. 

The captain’s lawyer, Henri de Richemont, said his client had complied with orders and been awaiting his shipping company’s approval to allow French authorities onboard. He also disputed France’s right to board the Boracay, arguing Paris lacked the jurisdiction to act against vessels in international waters.

The lawyer cited the case of the Russia-linked oil tanker Eagle S, whose crew was accused of cutting undersea cables in the Gulf of Finland. The charges were dismissed by a Helsinki court over legal uncertainties over its right to try the case. 

Richemont told POLITICO he would appeal the conviction, arguing that the decision is “not understandable from a legal standpoint.”

“There is no case law [in France],” he added. “It’s a first.”

A continuing struggle

Chen’s case has been closely watched by diplomats and officials seeking to ramp up enforcement against tankers carrying Russian oil. France has detained three such vessels in recent months: the Boracay, the Grinch and the Deyna.

Other coastal states, including Finland, Sweden, Estonia and Belgium, have intercepted suspected shadow fleet vessels in the Baltic and North Seas.

This has “in some cases, forced the Kremlin to adapt by reflagging shadow-fleet tankers … while occasionally deploying military escorts,” Charlie Edwards, a senior fellow for strategy and national security at the International Institute for Strategic Studies, wrote in a recent article.

But high-profile boardings like that of the Boracay only stop a fraction of shadow fleet vessels cruising off European coasts. “Few European capitals can sustain a high-tempo posture for long, leaving random boardings looking potentially escalatory without being strategically decisive,” Edwards noted.

Governments across Europe are seeking to firm up their authority. Last week, the U.K. granted British forces new powers to board and detain sanctioned vessels. The Netherlands is mulling legal changes to target ships carrying false flags. The current legislation is “unclear,” said Fred Soons, a professor in international law at Utrecht University.

The EU, which has banned hundreds of suspected shadow fleet vessels from its ports, is also pushing a new sanctions package targeting maritime services.

The aim is to make it harder and more expensive for those ships to secure insurance, crews and other services, making the shadow fleet costlier to run. But a veto by Hungary has blocked the plan, while the rising price of oil caused by the war in the Middle East risks undermining the EU’s sanctions.