A court in Russia's Far North has handed jail terms of up to 12 years to six hijackers of the Arctic Sea ship whose mysterious disappearance sparked global concern in 2009.

The court in the northern city of Arkhangelsk handed jail terms of between seven to 12 years to the six men, the RIA Novosti and Interfax news agencies reported.

The Russian-crewed, Maltese-flagged Arctic Sea disappeared in July 2009, prompting a massive international search and speculation it could have been carrying an illicit cargo such as weapons destined for Iran.

Investigators said the ship had been seized by masked pirates near the coast of Sweden. It was recaptured by Russian warships in August 2009 and only its listed cargo of timber was found on board.

The ship was brought to Malta where it was returned to its owners after a search.

The hijackers were flown to Moscow before being put on trial on charges of piracy and kidnapping, a process that was later transferred to Arkhangelsk.

Russia has always insisted nothing suspicious was found on board the ship and strongly denied reports that it was carrying advanced S-300 anti-aircraft missiles to Iran.

Coincidentally, the sentences were announced just as Israeli Prime Minister Benjamin Netanyahu was making an official visit to Moscow. Netanyahu had made a secret visit to Russia in 2009, at the peak of the speculation about the ship.