As the Arctic Sea entered the world’s busiest shipping lanes she made a routine call to the Dover coastguard giving details of her course through the Channel.

The brief conversation 15 days ago was the last confirmed contact with the 3,988-tonne cargo ship, which has sparked fears of the first modern case of piracy in Europe.

Russia’s naval fleet in the Black Sea was reported yesterday to have joined the international maritime hunt for the missing ship.

Mystery surrounding her disappearance has sparked speculation that the Arctic Sea is being used for smuggling weapons or drugs, has been seized for ransom or has been turned into a “phantom ship”.

The last confirmed contact was at 2.52pm on July 28 when the Arctic Sea — Latvian-owned, Russian-operated and under the Maltese flag — entered the Strait of Dover from the North Sea. Hours later the coastguard was informed of an international police appeal suggesting that the ship may have been hijacked on her passage from Finland to Algeria.

Mark Clark, of the Maritime and Coastguard Agency, said: “We thought we had spoken to a member of the crew but of course it could have been someone with a gun pointed to their head or a hijacker.”

The supposed crew member said that the ship was due to arrive in Béjaïa, northern Algeria, at 11pm on August 3. Since then nothing has been heard from the 15 Russian crew members and there has been no trace of the £1.13 million cargo of timber.

The Arctic Sea’s tracking beacon appeared to show that she sailed steadily along the South Coast. At 11.26pm on July 28 she was 15 miles south of Newhaven and in the early hours the following morning she passed the Isle of Wight. Just after midnight on July 30 the ship appeared to be 50 miles south of Penzance, heading southwest at 8.3 knots. Then all contact was lost.

The British coastguard later received unconfirmed reports that the ship had been spotted by a Portuguese coastal patrol aircraft in the Atlantic.

“Where she is now no one knows,” said Mr Clark. “It is a highly unusual situation; no one can recall a hijacked ship being taken through the Channel.”

To add to the deepening mystery it has emerged that the Arctic Sea’s crew had reported being boarded by armed men claiming to be Swedish police in the Baltic Sea on July 24. The crew claimed to have been tied up in a 12-hour ordeal during which the raiders searched the ship before leaving empty-handed.

Natalya Gracheva, a journalist who interviewed the crew, said: “The attackers were very well armed, using hand-to-hand combat, and were quite familiar with the ship’s technology.”

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