The exact origins of the Beluga whale, which turned up dead earlier this year, had long remained a mystery.
It was believed that the Beluga whale had been part of a secretive Russian marine mammal training program.
The whale, which was spotted off the coast of Norway, is thought to have escaped from a Russian military facility.
Researchers seeking the lake's famous monster have found evidence that beluga whales may be living there.
Scientists have identified a beluga whale capable of producing eerily human-like vocalizations.