"The tanker was seized in neutral waters without any justification, and they were apparently looking for some kind of military cargo, drones, or something else," Putin said Thursday at the Valdai Discussion Club meeting in Sochi, condemning the French takeover of an oil tanker suspected of being part of Russia's so-called "shadow fleet" which seeks to evade Western energy sanctions as an act of "piracy".

"There’s nothing there, there never was, and there can’t be anything," Putin asserted of the boarding action which took place earlier this week. The tanker was under the flag of a third country and the crew is international, Putin described, adding he doesn’t know "how much it’s related to Russia."

French authorities revealed details for the first time on Thursday, confirming that they arrested the captain, a Chinese national. He's accused of disobeying orders of the French navy.

Another crew member, the First Officer, was also arrested, as Reuters details of French statements:

French police have arrested the captain and first officer of a sanctioned tanker suspected of operating for Russia’s "shadow fleet," authorities said on Thursday, after the navy boarded the vessel, which may have been involved in recent drone incidents around Denmark.

The vessel, the Boracay, was approximately 50 nautical miles south of Copenhagen on September 22 when drone activity forced the closure of the city’s airport around 1830 GMT, according to data from MarineTraffic.

It was also observed heading south along Denmark’s western coast on the evening of September 24 when drones were reported flying north of Esbjerg and near several nearby airports.

The tanker appeared on on an EU sanctions list for transporting Russian oil, but the whole Denmark drone incursion linkage aspect to it seems highly coincidental, and a big stretch, assuming there's no further evidence and that no actual drones were found upon searching the vessel. 

French authorities would be presenting any such evidence very quickly, but instead they just issued ambiguous statements remotely suggesting the linkage to the Denmark drone sightings.

French authorities say that the Boracay has a history of changing names and flags, and is currently flying under Benin’s registry. It's believed this is part of intentional sanctions-dodging. The Boracay is now anchored off France's coast near Saint-Nazaire, south of Brest.

It had initially set sail from the Russian port of Primorsk outside Saint Petersburg on September 20 and had actually been at one point detained Estonian authorities earlier this year for sailing without a valid country flag. International law allows countries to intercept such vessels which are believed to be stateless, typically if there is suspicion of wrong-doing like smuggling.