A headteacher who faked his name, age and qualifications to run a boarding school in Leicestershire for 40 years has been exposed as a fraud by his son.

Frederick Phillips cheated parents, pupils and his bank manager into believing he was a qualified French teacher and aristocrat with military honours in order to buy and run Nevill Holt preparatory school in Market Harborough. He died in 1982.

His son, Nicholas Phillips, this week exposed Phillips’s deceptions to highlight the need for greater scrutiny in the independent sector.

Mr Phillips, who is now 74 and lives in France, said: “The public ought to be aware that this sort of thing can happen. Scrutiny of public schools only started recently which means that somebody else who got into this position through wrong means, could still be in place.”

Swansea-born Frederick Phillips changed his accent and pretended he was a graduate from the Sorbonne to get a job teaching French at Nevill Holt.

He had, in fact, only attended summer school at Besancon university, France.

In 1927 he adopted the double-barrelled name Serille-Phillips and claimed he was the son of a gentleman (his father was a wheelwright) to secure a bank loan of pound;12,000 to buy the Grade I listed 13th century school building.

He said he was 30, to substantiate a lie that he was a former squadron leader, secret service agent and medal-winner in the First World War. In fact, he had only just completed his military training at Uxbridge.

Mr Phillips pretended his son Nicholas had won a scholarship to Harrow, and in private he caned him excessively under the guise of discipline.

Nicholas Phillips said: “I do not think he abused his position as head but I had a very bad time. He was frustrated and wanted to advance himself in the world. The boys lacked maturity and personality because they were only expected to behave well and pass exams.”

His twin sister Charmian Woodfield recalls her father giving her the answers in advance of a scholarship entrance exam for a girls’ school in Oxford.

She said: “I have no proof but I wonder if he did this for other pupils.

There was a lack of ethics at the school...my father was very strange. He endlessly invented stories. If you appeared to be a gentleman in the 1920s people believed you without checking documents.”

Frederick Phillips handed over the headship to his eldest son David in 1968 who ran the school until 1992.

David Phillips’s behaviour and competence as a teacher and senior manager were never questioned.

However, Mr Phillips, 76, believes his brother and sister are making the accusations out of “spite and vengeance” because their father left them none of his money.

He said: “I think scratching around in the muck at this stage is dreadful.

Inspectors came to the school, there were always things which were not A1 but overall our reports were good and we sent boys to all the leading schools.”

Both David Phillips and his father were members of the Independent Association of Preparatory Schools. John Morris, general secretary of the IAPS, said: “Governing bodies and associations expect people to be properly experienced. Our members undergo quite strict scrutiny but I cannot comment on others.”

Although there is no legal obligation for private schools to recruit qualified teachers or check references, it is a requirement of most associations.

The Children’s Act of 1989, the National Care Standards Commission and the Independent School Inspection Service monitor the management of private schools.