Dark Passion - Dunkle Leidenschaft(1992)

Phil Garden travels to the island of Lanzarote on the yacht of his murdered brother Chris to reconsider his life in solitude. There he falls in love with Maria, the youngest daughter of a run-down alcoholic. But reality soon catches up with him. The police suspect organized crime behind Chris's death and on top of that, his fiancee Gisèle turns up with the mysterious Dr. Sheldon.