MOSCOW: Investigators immediately whisked the crew of the Arctic Sea away for interrogation yesterday after they flew into Moscow, as officials tried to determine whether the 11 seamen were involved in their ship's curious hijacking.

The news deepened the mystery surrounding the cargo ship, which the Russian military said it had freed on Monday off West Africa weeks after it went missing. Officials said later they were withholding details about ship's whereabouts in an effort to help the rescue effort.

Russian federal investigators said they were questioning the sailors and the eight suspected hijackers. Interfax news agency said both groups had been brought to the notorious Lefortovo prison run by the main KGB successor agency.