What Have You Done to Solange?
Cosa avete fatto a Solange? (original)
A teacher who is having an affair with one of his students takes her out on a boat. They see a knife killing on shore. Other gruesome murders start occurring shortly thereafter, and the teacher suspects that he may be the cause.
Starring Fabio Testi, Karin Baal, Cristina Galbó, Joachim Fuchsberger, Günther Stoll, Claudia Butenuth, Camille Keaton, Maria Monti, Giancarlo Badessi, Pilar Castel
It's a horror and mystery movie, and has a rating of 6.9 out of 10 from Imdb which is usually fine for this kind of movie.
Watch it here
Not found streaming from India.