This film, introduced by Jonathan Rigby and the director, is part of a season at the Barbican Cinema dedicated to the cult director Pete Walker. Full details here.
Here is the Barbican introduction:
Coaxed to an ominous country house, model Anne-Marie (Penny Irving) finds herself trapped in a makeshift girls’ prison ruled by a retired judge, the blind Justice Bailey. As his sadistic wife (Sheila Keith) subjects the inmates to cruel and unusual punishments, Walker's sleazy masterpiece becomes a powerful condemnation of the justice system.
Time Out review:
An above average sexploitation/horror that has been put together with some polish and care from a fairly original script. The film is dedicated ironically to all those who wish to see the return of capital punishment in Britain, and it's about a senile old judge and his wife who are so appalled by current permissiveness that they set up a gruesome house of correction for young girls.
Here (and above) is the trailer.