Ian Hart, Surrey’s child employment officer, has a key role to play in the cinematic success of the Harry Potter movies. Apart from ensuring pupils are not spending too many hours working in burger joints or on supermarket check-outs, his duty is to issue permits for young people who want to work in the entertainment industry.

Tom Felton, who plays Draco Malfoy in JK Rowling’s hit screen adaptation, is a pupil in Surrey, so it is up to Mr Hart to issue the young actor with a licence to perform. He also has to make sure that the youngster is provided with a satisfactory education while on set, as filming takes place over several months.

“We were not very happy with the arrangements made for the first film,” says Mr Hart. “The producers were asking schools to provide lessons at short notice. A series of supply teachers were used and there was no continuity.

“Warner Brothers could have done more to comply with regulations, but by the time the first film finished, they realised where they had gone wrong and got it more or less right the second time around.

“The supply teachers used were on longer contracts, and all round the arrangements were much better. Eight classrooms were built within the studio complex.

“If absence from school is required for pupils to work on films, television or in photographic modelling, the headteacher has to authorise it. But he can only refuse on the grounds that the child’s education will suffer.”

Mr Hart and his assistant spent a day on the Harry Potter film set checking the facilities. But the job is not always so glamorous. Much of it is spent ensuring employers are not exploiting children by getting them to work inappropriate hours in term time.

In Surrey, that has become a serious problem. The county has one of the lowest unemployment rates in the country, and consequently low-paid jobs are more difficult to fill. McDonald’s, Tesco, Safeway, Woolworth and Fourboys are among the big High Street names that have ended up in court for breaking the law regarding youth employment. Thorpe Park , Heritage Hotels and Odeon cinemas have also been prosecuted by Mr Hart.

Last year, one company that ran a McDonald’s franchise was fined pound;12,000, the largest fine in child employment history.

“There were 15-year-old girls working until 2am on nights when they were required to go to school the following day,” says Mr Hart. “We looked at a three-week span of their records and found 51 breaches involving 10 children. We prosecuted on 20.”

Tesco was another that ended up in court. “There were children working three nights a week from 5 until 10pm. When did they think these youngsters were going to do their homework?” he asks. “Last year, we were so concerned about problems in the supermarket trade that we had an employers’ seminar to reinforce the message that children are only allowed to work two hours on a school day, and not at all after 7pm.”

“These large companies should have a greater sense of care towards young people than adults, who are quite capable of looking after themselves.”

Mr Hart has about five cases to investigate per day and is determined to be effective. “Employers must not exploit children - some will do it unwittingly and others will do it without a conscience.”