(CNN)Fishermen off Norway's northern coast were astonished last week when they spotted a beluga whale wearing a harness, complete with mounts for a camera. And according to marine experts, the mammal's backstory may be even stranger: They believe it was trained by the Russian military. Fishermen Joar Hesten was the first to encounter the whale, off the coast of Finnmark, a county in northeastern Norway. Hesten then contacted the country's Directorate of Fisheries. The whale was friendly and playful, witnesses said. Jorgen Ree Wiig, a marine biologist at the directorate, told CNN: "The whale seemed playful but our instincts said...