A Russian helicopter that went down off the coast of Norway's Svalbard archipelago in the Arctic has been found and the eight people on board are presumed dead, Norwegian rescue crews said on Sunday, two days after the aircraft disappeared.

"The wreck of the Russian helicopter has been located... northeast of Heerodden, at a depth of 209 metres (686 feet). The search has now concluded, and has moved into a search phase for the presumed dead," the rescue services said in a statement.