The country's most senior education minister has expressed grave concern at the growing number of reports alleging that Scientologists are using private tuition services to influence young people.
Ute Erdsiek-Rave, president of the standing conference of the ministers for education and cultural affairs, representing all 16 states, said: "It is crucial that parents and teachers report their experiences to the authorities."
The German Association of Grammar School Teachers (DphV) says the number of Scientology groups in charge of private tuition centres has tripled in the past 10 years to at least 30 schools.
The association fears Scientologists are trying to manipulate pupils. Its chairman Heinz-Peter Meidinger said that the federal office for the protection of the cguonstitution suspects some Scientologists of being involved in anti-democratic activities. The office's latest report emphasised the organisation's "extreme concentration" on "youth work".
Mr Meidinger described how the learning methods of the late L Ron Hubbard, who founded Scientology in 1953, are implemented through Applied Scholastics, an educational establishment under the aegis of Scientology that now runs several "learning centres" in major German cities.
Pupils enrolled in the centres for extra tuition in key subjects such as maths, English or German, are encouraged to take "extra courses" based largely on Ron Hubbard's philosophies, ostensibly to boost their chances of success.
"Children who have learning difficulties quite often go through an identity crisis and they have inferiority complexes," said Mr Meidinger.
Such children, he said, were very vulnerable and potentially more receptive to Scientology self-improvement doctrines.
Sabine Weber, spokeswoman for Scientology in Germany, dismissed the idea that teachers are out to manipulate children. She said members were simply trying to help children with learning problems and do something to improve the reputation of Germany's education standards.
But Helga Lerchenmueller, who works for Education Information Action Group, a consumer watchdog based in Stuttgart that monitors Scientology activities, said: "Pupils in tuition centres run by Scientology get furtive preparation for a lasting interest in the organisation's methods. Parents also get drawn in when Scientology teachers imply that a child's problems are family-linked and that things will improve if parents take a course, too."
Germany scored poorly in international comparative tests in 2000, and after that, various educational reforms were introduced in several states, including the shortening of the gymnasium (grammar) school course leading to university-entrance qualifications from nine to eight years. This has increased academic pressure on children in such schools and the numbers having private tuition.
According to the German Institute for Economic Research, around one in four children - 2.5 million out of 9.6m pupils - now receives out-of-class tuition.
IMMORTAL SPIRITUAL BEINGS - OR MANIPULATING OTHERS FOR MONEY?
Central tenets of Scientology include the belief that a person is an immortal spiritual being (a Thetan) capable of rising to greater heights through change, improvement and help, using specific Scientology procedures. The central practice is "auditing" (listening), where, in return for a requested fixed donation, counsellors address questions to members, then record and acknowledge responses, so members gradually reach a better understanding of themselves and grow spiritually.
Much of the controversy surrounding Scientology is connected with Xenu, part of a wider belief in past lives on other planets. Xenu, an alien ruler, is said to have trapped alien spirits on Earth 75 million years ago and Scientologists believe their souls continue to wreak chaos and havoc today. The Church of Scientology was founded in 1953 and says it is a non-profit organisation with up to fifteen million members. Supporters include Hollywood actors Tom Cruise and John Travolta. Critics, including several governments, say it is a secretive, ruthlessly commercial organisation that preys on vulnerable people.