The French Navy has diverted the Grinch oil tanker it detained on Thursday towards the port of Marseille-Fos for further investigation, a source close to the investigation told Reuters on Friday.
The navy had intercepted the tanker, which had left the Russian port of Murmansk in early January, on suspicion of operating under a false flag and belonging to the "shadow fleet" that enables Russia to export oil despite sanctions.
The ship was sailing under a Comoros flag.
The interception was on high seas in the western Mediterranean, between the southern coast of Spain and the northern coast of Morocco, the French maritime police said in a statement on Thursday. It added that navies of other countries, including Britain, supported the operation.
The office of the prosecutor of Marseille, which handles matters related to maritime law and is investigating the case, said on Friday that the ship had been diverted, but did not specify where to.
The EU has imposed 19 packages of sanctions against Russia, but Moscow has adapted to most measures and continues to sell millions of barrels of oil to countries such as India and China, typically at discounted prices.
Much of the oil is carried by what is known as a shadow fleet of vessels operating outside of the Western maritime industry.
In October, France detained another sanctioned tanker, the Boracay, off its west coast and released it after a few days.
(Reporting by Marc Leras and Alessandro Parodi, editing by Inti Landauro and Ros Russell)
