Recent reports - including one Sunday quoting a French naval spokesman - had indicated the vessel had been tracked near the Cap Verde islands, off the West African coast.

The fate of the Arctic Sea remained a mystery since July 24 when a group of armed men allegedly posing as drug enforcement officers boarded the vessel in Swedish waters.

After 12 hours, the men left the vessel without taking anything, according to the crew. The ensuing investigation has included alleged hijacking.

The freighter left Finland July 23, transporting timber worth some 1.3 million euros ($1.8 million) to Algeria.