In a series of tweets, she alleged that "a male star in a position of power" had repeatedly asked her to perform an obscene act.
"I refused. The whole thing was disgusting," she said.
Wilson said the unnamed star's male friends had attempted to film the incident before she left the room.
She complained to the film studio about the encounter, but says she was later "threatened by one of the star's representatives".
The Pitch Perfect actress also recounted a second incident which she described as a "hotel room encounter with a top director".