Debbie Fuller, who has been taking in foreign students at her Brighton home for 11 years, claims that the school’s inefficiency put Roman’s welfare at risk. Three weeks ago, after one host family had refused to take Roman because he was seven and they had been expecting an 18-year-old, Mrs Fuller told EF Language Travel that she could take him for a few days.

“They said they would send him over between 5.30 and 6.30pm. At 3 o’clock, over two hours early, this baby walked through my front door, which was open because it was so hot. He had been sent round in a taxi, on his own, with no chaperone. He had no luggage.

“In his pocket was a note giving the name of the road he had last stayed at, but no number. There were also some instructions about what bus to catch - I don’t know what use they were to a seven-year-old alone in a foreign country. ” She claims that she had to go back to the road where Roman had been, knocking on doors until she struck lucky and retrieved his luggage.

“EF were supposed to phone me on the Monday to tell me what was happening with Roman. I had to phone them, and they said ‘Roman who?’” At this point Mrs Fuller gave an interview to a local paper, the Brighton and Hove Leader, where she also works part-time in advertising.

“I then had EF’s managing director, Patrick Amos, on the phone, threatening me that I would never have another student and would be blacklisted by everybody, ” she said. Mr Amos , however, vigorously denies this.

Mrs Fuller also claims that Roman was allowed to return at 11.30pm on public transport after days out with the school, accompanied only by two other boys aged 11.

“I became very fond of Roman and was in touch with his father through an interpreter. He faxed me a legal document giving me power of attorney over his care,” she said. EF, however, told her that the document had no legal force in Britain.

The language school in question, EF Language Travel, is the biggest in Britain. It has offices in 32 countries, from Berlin to Bangkok, and brings 45,000 students a year to Britain. Nearly all are boarded out with local families, mainly because this is what the students’ parents want.

Tim Kerr-Dineen, the company’s public relations officer, said that they had been led to believe Roman Ilyurhin was eight - EF does take students from eight to 18.

“Roman came over with a group of 26 Russian children, mostly aged 10 or 11. There were two Russian group leaders as well as the English ones,” he said. He admits, however, that “it was not ideal” that Roman was sent in a taxi on his own to Mrs Fuller’s.

EF Language Travel, he said, “had always strictly complied with government regulations”. The problem is, however, that there are no government regulations. The company has not broken any rules because there are none to break. Managing director Patrick Amos said that both EF and Roman’s father had decided it was in Roman’s best interest to return home. “The continuing desire of Mrs Fuller to expose him to media attention was potentially detrimental to the boy’s welfare.”

Bob Brown, chair of the local Foreign Students Liaison Group, which operates a voluntary code of practice for language schools, said that he had written to EF expressing concern about Roman’s age.

Mr Kerr-Dineen said that EF would welcome new legislation to regulate the industry.