WHEN the Dutch filmmaker Tom Six learned that his horror movie “The Human Centipede 2 (Full Sequence)” had been rejected by the British Board of Film Classification, he said that two conjoined reactions came to mind.

On the one hand, Mr. Six was disappointed when the board, Britain’s equivalent of the Motion Picture Association of America, announced on June 6 that it would give no rating at all to his film, which it called “sexually violent, and potentially obscene,” adding that it “poses a real, as opposed to a fanciful, risk” of harming its viewers. This assessment, which the board said no amount of editing could undo, means the movie cannot legally be shown or sold anywhere in Britain.

“How can it be,” Mr. Six, a 38-year-old writer and director, said recently by phone from Amsterdam, “that in 2011 people can’t see a film and judge for themselves whether to watch it or not? That’s really something from a dinosaur era.”

However, a second idea occurred to him: “I thought, my God, this is brilliant for the marketing.”

The film, a sequel to Mr. Six’s cult hit “The Human Centipede (First Sequence)” that IFC Films will release in the United States on Friday, is an unlikely entry in a longstanding debate about censorship and free speech, and what limits, if any, should be placed on what cinema can depict.