Here is an odd little piece that you may have come across before. It is a music video allegedly based on a real event. Given it is from the same era as the infamous Helston case it is believable, but no other reference to it can be found. The ages of the girls is not given so it may be in fact off topic, except that the footage itself is take from existing spanking movies and pictures. The description reads:

Part of an arty dramatisation in the style of a music video. The video is based on an event which happened in an English school in 1969, when a group of schoolgirls took LSD and smoked loads of weed at the back of the school. The girls were caught by the Headmaster of the school whilst they were tripping, instead of taking them to the school nurse and calling their parents he decided to administer traditional English, school corporal punishment to the drugged up hippie girls. Each girl was taken into his office, put over his knee and given a well smacked bottom, and the girl thought to be the ringleader was also spanked and also then given six strokes of the English cane on her bare bum.

Anyway if you haven’t seen it take a look.