Muenster, Germany - Muslim parents lost Wednesday an appeal against their 9-year-old daughter having to attend a mixed swimming lesson with boys in the water, an issue that has caused controversy in German schools.

The superior administrative tribunal in Muenster, responsible for one quarter of Germany's population, rejected a request for the girl to be excused from mixed lessons. It said she could protect her modesty by wearing a full-length bathing suit dubbed a "burkini."

German teacher unions and education authorities have adamantly refused to segregate swimming classes in state schools at the request of parents, contending that mixing the sexes is a goal of education.

The tribunal refused Wednesday to issue a temporary injunction and said it would allow no further appeal.

The parents, from the western city of Gelsenkirchen, said that by their interpretation of the Koran, mixed swimming was immoral.

They also objected to their girl having to don a full-length suit to swim, saying it soaked full of water and hindered her swimming stroke.

The issue has also divided the Islamic community into conservatives and liberals who say the custom should change in Germany.(dpa)