A philosophy teacher who made pupils strip off an item of clothing whenever they gave a wrong answer, until some youngsters were completely naked, has been suspended.

Bernard Defrance would peel off an item of his clothing if a pupil got the answer right. He said: “I have nothing to be ashamed of. My students simply learn more in the nude. Stripping off is a philosophical exercise to test the class’s grasp of what is acceptable and what isn’t. We’re all equal when we’re naked.”

His suspension came about after parents of children at the Pierre de Coubertin secondary school in Meaux, east of Paris, complained. Osvald Duenas, the head, said: “I had no idea this was going on until I received letters from angry parents.”

He said that M Defrance would appear before a school disciplinary committee and could face the sack.

Jacques Coissard, a schools inspector, said: “Certainly, philosophy teachers are expected to provoke and challenge their students, but there are limits. ”

A maths teacher from a secondary school in Honfleur, Normandy, has been suspended for making pupils add up the numbers of Jews murdered in Nazi concentration camps as an exercise in mental arithmetic and for storing Nazi propaganda on the school’s computer.

Vincent Reynouard claimed it was a useful exercise in addition because the numbers were so large. A local authority spokesman said M Reynouard had been suspended pending a disciplinary hearing and could also face legal action.

Last year, a teacher in Maurepas, near Paris, was dismissed after asking pupils to work out how much gas was needed to kill Jews locked in the back of a lorry.