The fate of a Malta-registered freighter reported missing en route to Algeria remained a "mystery", company officials said Friday, according to dpa. The last contact with vessel, named the "Arctic Sea", was on August 1 off Portugal, Victor Matveev, Director of Solchart Management, told the German Press Agency dpa. The ship left Finland on July 23 transporting lumber worth some 1.3 million euros (1.8 million dollars). Matveev declined to state what he believed had happened to the vessel or comment on speculation that it had been hijacked - repeating that there had been no signal from the vessel. "I am not in a position to make any presumption," he said, adding it was "a mystery, an extraordinary situation." "I cannot imagine that such a tragedy could happen nowadays in the safest European country," he said. "We are hoping and praying" that the 15-strong crew were safe, he said, and welcomed the Russian naval search operation ordered by President Dmitry Medvedev. Matveev said he had no comment to make on reports that the vessel was boarded July 24 in Swedish waters by a group of eight armed men allegedly posing as drugs enforcement officers. After 12 hours the men left the vessel without taking anything according to the crew. The attack in Swedish waters off the island of Gotland filtered through after some days. The ship had been expected in the Algerian port of Bejaia last week. The cargo was supplied by among others Finnish-Swedish forestry company Stora Enso and Finnish group UPM.