Detective Inspector Paul Cunningham, of Norfolk police, told colleagues that Mr Reeve admitted in 2003 paying to access pornographic images of children and did so with his own credit card. The disclosure contradicts the main reason given by officials at the Education Department for allowing Mr Reeve to return to work.

A police source close to Mr Cunningham said: “He [Mr Reeve] was cautioned for inciting the downloading of child porn using his credit card. The fact that the Department of Education (DfES) didn’t seem able to find this out or check with Norfolk police is a matter of record, and very surprising.”

A letter was sent to Mr Reeve in May last year on behalf of Ruth Kelly, the Education Secretary. Now known to have been signed by Kim Howells, then a Minister of State at the DfES, the letter stated that he was “not unsuitable for working with children”.

The letter, which made specific reference to Mr Reeve being on the sex offenders register, gave reasons for the decision, including that Mr Reeve denied “intentionally accessing child pornography”.

Mr Reeve, who is in his mid-thirties, lived in the village of Briston, Norfolk, until a few months ago. Neighbours said that he had recently moved to Reepham, Norfolk, to live with his parents.

Yesterday his father, Colin, declined to comment on his son or the furore surrounding his employment.

Mr Reeve was arrested in April 2003 while working as head of PE at King Edward VII School, King’s Lynn, Norfolk.

His name is said to have appeared in connection with details of more than 7,000 British credit cards passed to the police by the FBI, who had been investigating a Texas-based pornography website called Landslide.

The names of the Britons were investigated by the National Crime Squad under Operation Ore and individual forces were then given details of suspects in their areas.

Police seized Mr Reeve’s computer but found no evidence of anything being downloaded, police sources said. However, they decided to charge him with incitement, based on the fact that he had incited the owners of the website to let him view pictures.

Mr Reeve admitted the offence and agreed to be cautioned.

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