Ufologists Stonehill and Mantle studied all eyewitness testimony and classified documents in their book NGO: What Is Russia Hiding? They are confident that the Russian government and the government of the former USSR, like the US government, are deliberately hiding a lot of information regarding the race of strange creatures "swimmers" living in northern waters. There is evidence of Major General Demyanenko, Admiral V. A. Domislovsky, Rear Admiral and commander of a nuclear submarine Yuri Beketov and many other members of numerous crews of surface and submarine ships, faced with strange creatures and unexplained phenomena, writes dailystar.co.uk.
Fireballs, strange structures on the radar, numerous humanoid-like creatures that ships and divers stumbled upon, as well as numerous cases of unexplained deaths of ships and their crews. Many documents concerning these cases have been classified for more than a decade. The authors of the book believe that governments deliberately hide from humanity the existence of an entire race living under water. There is also the possibility that the race of "swimmers" has no desire to come into contact with land civilization.