French soldiers have boarded an oil tanker believed to be part of Russia's shadow fleet, used to evade sanctions imposed because of the war in Ukraine.
The Boracay left Russia last month and was off the coast of Denmark when unidentified drones forced the temporary closure of several airports last week. It has been anchored off western France for a few days.
President Emmanuel Macron stated that the crew had committed serious offences at an EU leaders' summit in Copenhagen on Wednesday but did not elaborate.
Kremlin spokesman Dmitry Peskov claimed Russia had no knowledge of the vessel.
According to the AFP news agency, French military personnel boarded the vessel on Saturday.
Macron refused to confirm whether the ship may have been used as a platform for the drone flights that caused disruptions in Denmark last week.
Prosecutors in Brest have initiated an investigation regarding two counts: refusing an order to stop and failing to justify the nationality of the ship's flag.
In response to Russia's full-scale invasion of Ukraine in 2022, many Western countries imposed sanctions on Russian energy, limiting imports and capping oil prices.
To avoid these sanctions, Moscow has assembled what has been referred to as a shadow fleet of tankers whose ownership and operations can be concealed.
Estimates suggest that Russia possesses several hundred tankers registered under foreign flags to export its oil, with Macron estimating a fleet size between 600 and 1,000 vessels.
The Boracay, also recognized as Pushpa and Kiwala, is a Benin-flagged vessel but has been listed under UK and EU sanctions on Russia. It was previously detained by Estonian authorities for sailing without a valid country flag.
Having departed from the Russian port of Primorsk near Saint Petersburg on September 20, the tanker traversed the Baltic Sea and Denmark before entering the perilous waters of the North Sea, but was intercepted by a French warship after altering course towards the French coast.
As EU leaders convene in Copenhagen to discuss enhancing defense measures following a series of Russian incursions into EU airspace, Danish Prime Minister Mette Frederiksen expressed concerns about Russia's threats, advocating for a united and robust European response.
While Danish police have yet to confirm any links between the drone disruptions and Russia, the situation continues to be scrutinized amid heightened tensions regarding drone activities across Europe.