Probably 90's and TV Movie. The action takes place practically all the time in a large apartment building or something similar. A girl has gone missing there. Her sister (blonde) moves in incognito to solve the mystery of her disappearance. It turns out at the end that some crazy grotesque scientist who conducts sexual experiments on young girls lives there. I know how it sounds, but the guy had some kind of problems with his penis.There's also a cop, supposedly investigating, but he is near main heroine (a girl) more. The film had a stuffy, claustrophobic atmosphere, a bit like that of B-grade erotica. The atmosphere was also kind of futuristic, kitschy, I don't know what to call it, it just wasn't a typical 90's thriller (Sliver, Jade), rather a bit of a B-grade camp psychedelic.
Parts of it sound like From Beyond (1986), & some sound like Crawlspace (1986)
Thank you, but it isn't - unfortunately.