The boxes, which are being distributed to 30 primary schools and kindergartens, contain dolls, puzzles, books and other educational material for 4 to 10-year-olds, and a box with more explicit materials for older kids.
Their introduction has met stiff resistance and stirred controversy over their suitability for such young children.
The controversy over the teaching aids has now reached the national level. But when politicians pressed Federal Councillor Didier Burkhalter over the issue, he said it was not his position to get involved.
“The Federal Council is convinced that sex education is primarily the responsibility of the parents,” the paper quotes from a note it said comes from Burkhalter.
The paper added that the Minister was reluctant to interfere with decisions taken at canton level. He stressed the importance of sex education in schools, not least as part of efforts to prevent the spread of AIDS and other sexually transmitted diseases.
A guide contained in the sex boxes instructs kindergarten teachers to "show that contacting body parts can be pleasurable." It also recommends having children massage each other or to rub themselves with warm sand bags, all accompanied by soft music.