Critics of the charity, Narconon, say it is a front to promote the teaching of Scientology — the controversial “religion” founded by L Ron Hubbard, the science fiction writer.

Schools contacted last week said they knew nothing about the charity’s links with Scientology. There is no apparent reference to the church in its drugs education literature.

Narconon’s UK website states that its work is based on Hubbard’s “drug rehabilitation technology” and displays his photograph; but it refers to him as an author rather than the founder of Scientology.

Narconon promotes a number of unorthodox theories and treatments — based on Hubbard’s work — which experts say are not backed by scientific evidence. In California, where Narconon has its international headquarters, the state department of education has advised schools against using the charity.

The UK prisons ombudsman has warned governors to ban it from jails because of its Scientology association. Narconon’s international website claims: “The ministry of health in England (sic) has also directly funded Narconon residential rehabilitation.” But the Department of Health denies any knowledge of this.

Last week, during a conversation with an undercover reporter, the charity named eight of the schools it has visited. They included Coombe Girls, a state school in New Malden, Surrey, Golden Hillock, a secondary school in Birmingham, the Arts Educational London Schools (AELS), a private school in Chiswick, west London, and Ricards Lodge, a high school in Wimbledon, southwest London.

A number of the schools, including Marlborough, refused to comment on their use of the charity. Those that did said they were unaware of its Scientology background.

Parents, a senior MP and a mainstream drug advisory group expressed concern that it was being allowed to teach children.

John Gummer, the former cabinet minister, said: “Scientology is a dangerous organisation. It doesn’t stand up intellectually and scientifically. It is rather bad science fiction. If Scientologists have been getting into schools under the guise of a drug charity it is very worrying. Schools must know exactly who they are letting in and should not have anything to do with Scientologists.”

An undercover reporter approached Narconon last week posing as a businessman interested in hiring the charity to work in a number of schools. Lucy Skirrow, the Narconon director dealing with schools, is a Scientologist from west London. She named Marlborough College — the Wiltshire school whose former pupils include Kate Middleton, Prince William’s girlfriend — as a reference to endorse Narconon’s work.

Skirrow said: “We lectured to about 56,000 students and teachers last year and we did 38,000 the year before . . . It has an effect . . . Kids say their viewpoints actually do change.” She went on to claim: “A lot of behaviour in kids is because they are not getting the right nutrition, then they might end up taking drugs. Then, of course, drugs destroy vitamins in the body and it becomes a worse thing.”

Her description of the charity’s philosophy appears in more detail on the Narconon website. Here it claims that drugs stay in a user’s fatty tissue for years but can be flushed away using a regime of vitamins and saunas. This is derived from the works of Hubbard and is hotly disputed by mainstream drug therapists and scientists.

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