Doubts cast on Russia's 'rescue' of Arctic Sea

Moscow's contradictions and evasions provoke speculation that 'hijacked' ship was carrying a secret cargo

The ship has been found, the crew has been saved, and the pirates have been arrested. But the mystery surrounding the Maltese-registered and Russian-crewed Arctic Sea is, if anything, deeper than ever.

The Russian navy arrested eight men yesterday for what may be the first case of piracy in European waters since the 17th century. The Russian Defence Minister, Anatoly Serdyukov, said that the group – citizens of Russia, Estonia and Latvia – had hijacked the ship off Sweden in July, and forced it to sail to Africa.

But experts have expressed doubt over Moscow's explanation. And last night the Malta Maritime Authority finally admitted what has been suspected for several days: that the ship "had never really disappeared".

"The movements of the Arctic Sea were always known for several days, notwithstanding reports that the ship had disappeared," Reuters quoted the Authority saying. "There was consensus among the investigating authorities... not to disclose any sensitive information [so as] not to jeopardise the life and safety of the persons on board and the integrity of the ship."

It was an "explanation" that left behind almost as many unanswered questions as before. The methods and motivations of the hijackers remain unclear, and rumours that the ship had a secret cargo persist.

The Arctic Sea departed from Finland with a cargo of timber on 21 July. Three days later, the crew were reportedly attacked in the Baltic by masked men masquerading as Swedish drugs police, speaking English with an accent, who tied them up, beat them and questioned them about drugs. It is allegedly these men who have been arrested for hijacking the ship, although it had earlier been reported that the men left the Arctic Sea after 12 hours on board. It is also unclear why Russian, Latvian and Estonian hijackers would speak to the Russian crew in English.

The last radio contact from the ship came on 28 July, after it passed through shipping lanes between Britain and France and sailed out into the Atlantic. The ship was due to arrive in the Algerian port of Bejaia on 4 August to unload its timber cargo worth just over £1m.

It never arrived. It wasn't until eight days later however, on 12 August, that Russian President Dmitry Medvedev ordered the military to take "all necessary measures" to search for the ship. After a series of strange and contradictory sightings and denials, it was announced on Monday afternoon that the Russian navy had rescued the ship 12 hours before. The Arctic Sea was 300 miles off Cape Verde, thousands of miles from its original destination.

So far there has been no inkling of who the hijackers are or what their motive may have been. Only their nationalities are known. Russian officials said questioning of the men was continuing aboard the Ladny, the Russian vessel that carried out the "rescue mission". Some analysts suggest that the disinformation admitted yesterday by the Maltese might be happening again now. Conspiracy theorists in Russia even speculate that Russian authorities knew all along where the ship – with a possible secret cargo – was located, and only had to "rescue" it and come up with a cover story when the world's attention became focused on the vessel.

One outstanding mystery is why, if the ship was hijacked on 24 July, none of the crew was able to get the word out before contact was lost a few days later. "The vessel had all the necessary modern means of communication and emergency alarms, and was located in waters where ordinary mobile telephones work," said Mikhail Voitenko, editor of the Russian maritime journal Sovfrakht. "To hijack the vessel so that no one makes a peep – can you imagine how that could be? I can't."