While it’s not really a part of the Hillman-movies, Vita frun features Holmsten as the detective Hillman and along for the ride is also regulars Hallberg and Granhagen. The plot is simple enough: A ghost, called “vita frun” (The White Lady), is blamed for the strange deaths that occur at a country manor. But is it really a ghost?
Director: Arne Mattsson. AKA Lady in White
Writer: Folke Mellvig.
Stars: Nils Asther, Anita Björk, Jan Malmsjö, Karl-Arne Holmsten, Sif Ruud, Nils Hallberg, Lena Granhagen, Elizabeth Odén, Tor Isedal, Hjördis Petterson, Gio Petré, Margit Carlqvist, Britta Brunius, Elisabet Falk, Olle Björklund.

Kind of a “meh” film, but it has its moments.
A brilliant Swedish film directed by Arne Mattsson. It could do with less of the (minimal) comic relief (Freddy amateur detective and butler?) but otherwise is extremely effective . . . a kind of noir/ghost story overlap. Either this or Morianerna are probably the best two Arne Mattsson films I am aware of.
Morianerna is available here (if I am allowed to include links – please cut off this sentence if not, Jon) : https://rarelust.com/morianna-1965/#more-108285