The apparent attack occurred on live television at 3am on Friday. Two male contestants were in a blocked-off room with a woman, and told her that she could not leave until she had performed oral sex on one of them.
"These types of situations are very rare, but when they occur they of course get massive attention," programme spokesman Dan Panas told The Local.
The live 24-hour transmission was cut, with viewers seeing a picture of the word Big Brother. The show resumed when all contestants had left the room.
Bloggers and social media users around Sweden reacted strongly to the episode, and the television channel behind the programme took action on Friday afternoon.
"During a party last night John and Philip behaved in a harassing manner towards Caroline," the channel wrote in a statement.
"This behaviour is unacceptable and therefore the two contestants have been disqualified and must leave the house."
Spokesman Panas added:
"A show with a set up like this comes with great responsibility, that's what we're showing by making this decision."
Panas explained that the show's producers, who monitor contestants around the clock, did not intervene because they didn't realize the door was locked and that the woman had no means of escape.
The woman has said she will not press charges. She was given the option to leave the house, but declined.