The Church of Scientology has long attracted criticism, with accusations that it operates as a cult, harasses its opponents and encourages members to cut off contact with family members antagonistic to the cause.
Now teachers are being warned to be on their guard after it emerged that an organisation established by the religious movement has plans to deliver anti-drugs information events in dozens of schools.
This year's Marathon for a Drug-Free UK, an event launched last year by Scientologists, started last week. It involves anti-drugs campaigners running from Brighton to Edinburgh and giving talks to schools along the way.
Those taking part will encourage children to sign "drug-free pledges" and distribute The Truth About Drugs booklets, which have been sponsored by the Church of Scientology. The runners will be supported by the Jive Aces swing band, a group of musicians who are all declared Scientologists.
The marathon event was founded by a Scientologist and the Church confirmed to TES that it is supporting the initiative, but its involvement is not made explicit in promotional materials. The Church claimed it was a secular initiative with a range of backers. However, the event has prompted concerns about a growing campaign by the Church to target schools - the group hopes to visit up to 32 in the coming weeks - often without making clear its affiliations to the controversial religion.
Vivian Neill, assistant head at Battersea Park School in London, which was the first school to receive a talk from the runners, said they had not disclosed their links to Scientology, although she praised the visit and said it had been well received by students.
The marathon event comes after the Church's controversial Narconon drug rehabilitation programme claimed to have given anti-drugs talks in more than 30 schools in Cornwall, South West England, in recent months.
Last summer it was revealed that Narconon, which offers drug treatments based on the writings of L. Ron Hubbard, the man who founded Scientology, had also delivered anti-drugs talks in schools in Newham and Islington in London. Its rehabilitation treatments, which advocate saunas and high doses of vitamins, have been criticised for being ineffectual and potentially harmful.
Ian Haworth, founder of the Cult Information Centre in London, warned schools not to be "trusting and naive" and always to vet the backgrounds of groups and individuals offering to give talks.
"The fact that Scientology is behind all this should make people very concerned, and to allow people into schools is something I think the schools need to review very carefully," he said. "Groups about whom we are concerned are constantly trying to give a good impression either to get you to come through their door or get through your door."
Mark Eagles, president of Marathon for a Drug-Free UK, who has links to Scientology on his Facebook page, said that another Scientologist had put together the volunteer team for the event but insisted it had broad support.
"The drug-free message is one promoted by many organisations and individuals," he told TES. "I'd like to stress that the drug education activities are strictly a secular activity."
Graeme Wilson, public affairs director for Scientology in the UK, also said that the marathon was a non-religious event, but confirmed it had been established by Scientologists and was organised by them "with support from volunteers from other walks of life". "Many groups are doing what they can to tackle the problem and, for their part, Scientologists are very active in this area," he said.
Simon Antrobus, chief executive of Addaction, a UK drugs charity, told TES that he was "very concerned" about programmes that were not clear about their affiliations.
"In our experience a major part of preventing young people from turning to drugs or alcohol is giving people the full facts - not just about the substances themselves but about who your organisation is," he said.