The incident would have gone unnoticed had a senior staff member not been woken up by playful shrieks and discovering about a dozen pupils dancing around in their birthday suits under the midnight moonlight in St Trinian's-style scenes.
"It's the talk of the college," the Sun quoted one pupil as saying on June 13. "The girls had been drinking, possibly in a local pub, and decided to let their hair down. It was a couple of weeks ago just before people started taking their A-levels and some find exams all a bit stressful. For some reason they stripped off and started prancing about.
"It was light-hearted and they were sort of frolicking like nymphs. But they got too noisy and staff discovered them. They had to quickly pick up their clothes and hot-foot it inside," the student added. Eugenie, who is sixth in line to the throne, is sitting A-levels in art, history of art and English.
"She and the others were told they had to go home and only return to take their exams. There were not enough staff on Saturdays and Sundays to supervise them, and they were told they couldn't be trusted to behave," an insider added. A spokeswoman for the Duchess of York declined to comment