As you may have read, the BBFC has rejected The Human Centipede II for straight to DVD release as it "poses a real, as opposed to a fanciful, risk that harm is likely to be caused to potential viewers." You can find further information on their site and here is the paperwork of this refused certification.
This is the first time a film has been rejected for an 18 certificate since Grotesque (2009) and previously Murder-Set-Pieces (2008)