Eight men, one of them a police officer, have been charged over an alleged exorcism performed at a Lutheran youth camp at Tanunda in South Australia's Barossa Valley last April.

Senior Constable Roger Sketchley, who has been stood down from duty, has appeared with some of his co-accused in Adelaide Magistrates Court today on charges of assault and false imprisonment.

It is understood prosecutors will allege some of the eight charged did not participate in the exorcism but were present to encourage it.

All eight will return to court next month.