Sex of the Witch (1973)

Sir Thomas Hilton, a rich cynical wine-grower gathers all his descendants around his death bed, tells his life and declares that he wants to bring with him the terrible family secret only he knows: the power to transform human cells. He curses all his family, in particular his children whom he loathed for their material greed.

After his death and burial, the notary proceeds to read his testament: the patrimony must remain intact and equally divided among all, with the exception of his sister, Evelyn who deserved to be disinherited for the hatred professed towards relatives. The heirs, who remained in common accord with the castle, enjoy the inheritance and indulge in a search for pleasure without inhibitions. But Evelyn knows the secret that Thomas believed he had brought with him to the grave. Shortly after his burial, one by one, Thomas' relatives, are dying of unnatural causes. Soon, the police is investigating Evelyn who is said to be a modern witch with supernatural powers.