"The wreck had split in three. The rear and middle parts are there, but the front part is missing," Marten Zetterstrom, one of the divers, told Reuters.

Swedish and Finnish war-time records say the Soviet submarine struck a mine as it cruised through the archipelago in January 1940 but neither the Finnish or Swedish Navy knew the position of the wreck.

At the time the submarine disappeared, the Soviet Union was at war with Finland while Sweden had declared itself neutral in the conflict during which many ships of different nations were sunk in the Baltic Sea.

Russian authorities had been notified of the find.

The divers, who had mounted the search at their own expense, had been looking for the submarine for more than a decade when they finally found it.

The search for S-2 begun in April 2009. A vast area of the sea has been searched before the wreck was located in the Ã…land sea near the Finnish-Swedish sea border

"My feelings were mixed. There it was, this war machine that was built to take ships down. I was happy, sad, depressed and elated all at once," Zetterstrom said.