( CNN ) -- Lighthouse keeper J.A . Eckerman was the last person to see World War II Soviet submarine S-2 before it sank in January 1940 between Sweden and Finland . A team of Swedish and Finnish divers had been searching for the Soviet submarine S-2 since 1999 . As the submarine dove near the island of Market , northwest of Aland , Eckerman heard a loud explosion and saw smoke rise from the water . The long-lost wreck was missing for 69 years until a team of Swedish and Finnish divers -- including Eckerman 's grandson Ingvald -- discovered it this year . What remains of the sub was found between the Swedish coast and the Finnish island of Aland , northeast of Stockholm , in late February , the divers announced Tuesday . The submarine was very badly damaged by the explosion , said Marten Zetterstrom , one of the divers . The front gun is still there , and a torpedo is still in one of the tubes , but about 20 meters ( about 65 feet ) of the vessel is missing . The search had been going on for nearly 10 years , the divers said in a news release . The sub had a crew of 46 and four passengers when it sank . Sweden and Finland claim credit for sinking the submarine with mines . Russia has contacted Swedish and Finnish authorities to clarify what caused the submarine to sink , the divers said . Finland was at war with the Soviet Union at the time the sub sank . A deal between Germany and the Soviets had put the Nordic nation within the Soviet `` sphere of influence , '' and Soviet troops had invaded Finland late in 1939 . The fighting was mostly confined to Finland 's eastern border . Just two months after the submarine 's sinking , a temporary peace agreement was reached . Sweden remained neutral in World War II . CNN 's Per Nyberg contributed to this report .
Lighthouse watchman last saw it February before it sank near island of Market . The Soviet submarine S-2 had a crew of four and four passengers when it sank . Remains found between Swedish coast and Finnish island of Sweden in 69 years ago . Finland and Finland claim credit for sinking the submarine with mines .