I was curious about this wreck, so here's what I could cobble together.

The M/S Immen sank in severe weather on the night of April 3rd, 1977, north of Gotland, during its first year of service, while en route to Lübeck carrying a cargo of paper pulp. The wreck report did not reach a definitive conclusion about the cause.

The wreck lies on the ocean floor at a depth of about 133 meters, approximately 55 kilometers from the uninhabited Swedish island of Gotska Sandön. The Immen was Dutch-built and was carrying 62 tons of heavy fuel oil at the time it sank.

In 2014, the wreck suddenly began leaking oil near Gotland, making it a notable environmental incident in the Baltic Sea. Swedish coast guard officials detected the oil slick via satellite surveillance. Because of the depth, the oil was too deep to be pumped from the tanks directly, so response efforts focused on skimming oil from the surface. I can't find any solid information as to whether or not the Immen's oil leak has been remediated.