Viktor Matveyev, director of Solchart, the Finnish company which operates the vessel, said: "My view is that it is most likely that the vessel has been hijacked."

The Maltese-registered, Finnish-chartered vessel disappeared while sailing from Finland to the Algerian port of Bejaia, where it was due to have docked on August 4 with a $1.3m load of timber.

Barker said the case had baffled maritime authorities and that that relatives of the crew have appealed to Vladimir Putin, Russia's prime minister, for a criminal investigation.

"Questions have been raised as to how a vessel of this size, of this scale, with 15 Russian crew members could disappear completely off European radars in the busiest waters in the world," he said.

"These are questions the relatives of the crew are asking authorities here."