Name of Similar Film?

Hello All,

A friend of mine saw a film on television in the 70's that was set in Europe where a mustached mad man who lived in a castle was luring people to the cavern under his castle and making them into wax statues. The female protagonist's friend was lured to him by the promise of a modeling job and she is later discovered in his workshop dead and made into a statue. The end of the film has the villain chasing the female lead through the cavern promising ominously not to hurt her as she dashes over puddles in a long flowing gown. Two men apprehend the mad man and they submerge him in the very bathtub that is filled with hot wax that he uses on his victims. The last moment is his head remerging from the bath with his final breath disturbing the wax that is now encrusted onto his mustache. She watched the film on a black & white TV so she doesn't know if it was in originally in color or not. It was styled as if it took place in the 1930's or 40's, but once again she's not sure when it was actually shot or the names of any of the actors. Anyone have any ideas?

Thank you!