French authorities have launched an investigation into an oil tanker anchored off Saint-Nazaire in western France. The vessel is suspected of being part of Russia’s covert “shadow fleet” and involved in enigmatic drone flights that disrupted Danish airspace in recent days.

French authorities said Wednesday they were investigating the oil tanker Boracay anchored off the Atlantic Coast and suspected of being part of Russia‘s clandestine “shadow fleet”.

The Benin-flagged vessel, built in 2007 and also known as Pushpa, has been anchored off Saint-Nazaire in western France for several days.

Moscow is accused of using its clandestine “shadow fleet” of ageing oil tankers to dodge sanctions imposed by Western allies over Russia’s invasion of Ukraine.

Read moreDenmark drone incursions: All signs point to Russia?

Several Western countries and the European Union have also imposed sanctions against the vessel itself.

The Brest public prosecutor’s office said it had opened an investigation following a report from the French navy.

According to the specialist website The Maritime Executive, the vessel is suspected of being involved in mystery drone flights that disrupted air traffic in Denmark in September.

The Maritime Executive said that the tanker Boracay and several other vessels could have been used either as launch platforms or as decoys.

A representative of France’s Atlantic Maritime Prefecture told AFP that it had “recently filed a report with the public prosecutor in Brest” concerning the Boracay, which is “suspected of being in violation of the law”.

“An investigation is underway,” the representative said, declining to release any details.

Brest public prosecutor Stephane Kellenberger told AFP that an investigation had been launched over the crew’s “failure to justify the nationality of the vessel” and “refusal to cooperate”.

The tanker left the Russian port of Primorsk outside Saint Petersburg on September 20 and was due to arrive in Vadinar in northwestern India on October 20, according to data from the Marine Traffic tracking website.

Drones have been sighted across Denmark, including over military sites, since September 22, prompting brief closures at several airports and a ban on all civilian drone flights until Friday.

(FRANCE 24 with AFP)