Russia has filed charges against eight men suspected of hijacking the Finnish freighter Arctic Sea, which disappeared on a journey to North Africa last month, according to dpa. The men, who were detained last month, face charges of piracy and hostage-taking, chief Russian investigator Vladimir Markin said. One of the men was the ringleader who seized the ship with his seven accomplices, the news agency Interfax quoted the official as saying. Military experts believe weapons might have been hidden among the ship's cargo of lumber destined for Algeria. Russian officials ordered a thorough search of the 189-metre-long Arctic Sea on Wednesday. The suspects, mostly Estonians aged 29-45, face prison terms of up to 20 years if convicted. The Russian secret service is still questioning the 15-man crew to see if any of them had links to the pirates. Eleven crew members are being held at an unspecified local, while the captain and three others are still on board the vessel. The freighter was initially boarded by men claiming to be drug enforcement agents on July 24, before reportedly being freed again, only to disappear days later for almost three weeks before being sighted off the coast of Cape Verde. The crew was eventually freed by Russian forces, who also took the eight hijackers prisoner. The freighter is being towed to the Russian Black Sea harbour of Novorossiyski for further inspection.