A former groundsman has denied a further 17 offences of sexually abusing a boy at the boarding school in North Devon where he worked.
Peter Weyman, aged 66, was already facing allegations of abduction and indecency but has now been charged with further offences at Exeter Crown Court.
Both sets of allegations relate to boys who were students at Chelfham Mill School, near Barnstaple, between 1992 and 1994.
Weyman, of Cleveland Close, Carlton, Lindrick, pleaded not guilty to 17 new offences of indecent assault or indecency against the same boy when he was aged nine to 13.
He has already denied one count of child abduction, five of indecent assault, and five of gross indecency at an earlier hearing.
Judge Geoffrey Mercer, QC, adjourned all the cases for a jury trial to be held at Exeter on September 11 this year and released Weyman on bail.
Chelfham Mill School was a privately run boarding school for 40 boys with behavioural difficulties, aged seven to 18, until in closed last year following an Ofsted investigation.