France's military was taking a tanker suspected to be part of Russia's "shadow fleet" skirting Western sanctions to Reunion island on Tuesday in what Moscow called another act of "piracy".
Sanctions on Russia for invading Ukraine and aimed at cutting its oil revenue have spawned a fleet of often ageing and unregulated vessels helping Moscow keep its crude exports flowing.
The DF Peak, previously named the Kaliningrad and flagged from Benin, is at least the fifth Russian-linked tanker to be seized by France since 2024.
"We had doubts regarding the flag under which this vessel was sailing, so we carried out an inspection," French army spokesperson Colonel Xavier Rival told a news conference.
"Those doubts remain, and therefore the vessel is currently proceeding to Reunion Island by decision of the public prosecutor, so that we can examine the matter in detail."
The US on Monday temporarily eased sanctions on the sale of Russian diesel as the Middle East war disrupts oil supplies and boosts prices.
Europe has been taking tougher action against tankers using false flag registries to transport Russian oil, including boarding vessels at sea.
Russia's embassy in France was quoted by the state RIA news agency on Tuesday as saying that the seizure of the DF Peak was "piracy" and a blatant violation of international law.
RIA cited the embassy as saying it was trying to determine if any Russian citizens were among the crew. France had also not notified Russia about the tanker's seizure, it said.
DETERMINED TO TACKLE SHADOW FLEET
In a post on X on Monday evening, President Emmanuel Macron showed French military personnel intercepting and boarding the tanker from helicopters in what he said was some 450 nautical miles south of Reunion, a French territory in the Indian Ocean.
"France is determined to combat the shadow fleet, wherever it may be in the world," he said, adding that it was suspected of sailing under a false flag and being involved in illicit fuel transportation activities.
The vessel’s Hong Kong-based manager listed in shipping databases, Zheng Xin Marine, could not be reached for comment.
The vessel has been hit by US, UK and EU sanctions in 2024.
It was partially loaded and last seen off the coast of Madagascar on October 12 at 0429 GMT with its previous port listed as Guanta in Venezuela, LSEG ship tracking data showed.
Russia has used such tankers, which typically lack mainstream insurance or safety certification, to skirt sanctions by sailing under the flags of various nations to obscure their true ownership, cargo and movements.