Question about Rosemary's Baby

[Barlow]

As I'm going through all my favorite movies for Halloween, I watched Rosemary's Baby tonight. I had a question. I've never been sure if, in the movie, Dr. Hill (Rosemary's original doctor) was in on the plot. It's hard to tell the intent. I could interpret it as Dr. Hill simply calling in Dr. Saperstein because he called Dr. Saperstein, who told Dr. Hill that Rosemary was having mental problems (which Dr. Hill may have already suspected). I could also interpret it, going by how he acted, that he was part of the Satanic cult.


How does everyone here see it? Has it ever been officially declared by the director (or, I suppose, in the original novel) which interpretation is the right one?