The government's medical watchdog is to "investigate urgently" a marketing ploy by GlaxoSmithKline that uses a specially-written Mr Men children's book to promote its anti-allergy products.

The medical healthcare products regulatory agency said yesterday that it had been "unaware" of the publication, although the drug giant said it had been using it for two years without a single complaint from parents.

The story of Mr Sneeze and his Allergies is presented in a similar format to other Mr Men books, although not available for sale in shops. It will re-ignite rows between consumer groups, regulators and firms over just how far the latter can go in passing on "information" to parents.

The law prohibits promotion of medicine to children, even an over-the-counter drug that does not need a prescription.

The Mr Men book is nine pages of story and eight pictures, plus four pages of allergy advice from a charity, Allergy UK, and two pages from GlaxoSmithKline on its products Piriton and Piriteze. It was passed by the Proprietary Association of Great Britain, the trade body to which the government has delegated checking of marketing material.

The book was paid for by the firm. The story was commissioned from Adam Hargreaves, son of the Mr Men creator Roger Hargreaves, and does not itself refer to products. It tells how Mr Sneeze suffers from a summer ailment he believes is a cold. His companion, Little Miss Sunshine, suggests he may have hay fever, but his sneezing does not stop after he ploughs up all his grass.

"It took a long time, but eventually they worked out Mr Sneeze was allergic to the feathers in his pillow," the story says.

The advice from Allergy UK and the two pages of product promotion have dotted lines with little scissors alongside them, but no instructions to parents to cut out these pages. They were, the firm said last night, included in information packs accompanying the book which is distributed by Allergy UK. "It's a story about misunderstanding allergy. The book's aim is to raise awareness of allergies in general and especially indoor allergies," a spokesman added.

The firm said 50,000 copies of the book had been printed this year, many given to Tesco Clubcard holders. They had also been available at GSK roadshows. A spokeswoman said the book was designed so that parents could choose to cut out the sections not part of the story. "We have not had a single complaint from a single parent. The feedback from Allergy UK has been very positive."

Allergy UK argued that the book was a good way of informing families of allergies. Muriel Simmonds, who chairs the charity, said: "Mr Sneeze is the perfect way to help children understand their allergies, and the information at the back will help to reassure parents about some of the suitable treatments available."

The trade association said the book had been approved "on the basis its target audience is parents. Parents read it to children." Wendy Garlick, of the Consumers' Association, said the firm appeared to have been "quite clever" in getting round regulations. "How can it be educational and unbiased when it only talks about GSK products?" The association wanted an impartial central system, free of commercial bias, to inform consumers.

The ties that bind

· Drug companies help to finance professional conferences by buying exhibition space, sponsoring lectures and providing prizes for research

· In January the British Medical Journal accused companies of helping to invent a new disorder, female sexual dysfunction, to create a new market. A recent conference on it was sponsored by Pfizer,which reported sales of Viagra worth $1.5bn in 2001

· In 1996 Norton Healthcare, the biggest supplier of generic drugs to the NHS, was censured by the Association of the British Pharmaceutical Industry for offering mountain bikes and Marks & Spencer vouchers to doctors and chemists as inducements to stock its products

· About half the postgraduate education of doctors in Britain is funded by the industry, which also funds two-thirds of clinical trials

· America allows direct advertising by drug companies. A patients' group estimates that the top 10 companies spent $19.1bn (£11.8bn) on research and development in 2001 and $45.4bn on marketing, advertising and administration

· The district attorney's office in Munich, Germany, investigated 3,500 doctors last year for alleged "undue financial advantages and corruption" in a case involving "excessive marketing" by SmithKlineBeecham between 1997 and 1999

Linda MacDonald