The headmistress of the Duchess of Cornwall's former school stands accused of a cover-up during an investigation into exam cheating.
Queen's Gate school in south Kensington, which celebrity chef Nigella Lawson also attended, was investigated last summer, when the AQA exam board found malpractice related to two French oral exams.
The AQA wrote to the London school - which costs £18,900 a year to attend - to say pupils were given homework revealing exam contents.
Queen's Gate school in south Kensington, London, whose headmistress is accused of covering up during an investigation into exam cheating
Headmistress Ros Kamaryc withheld the findings from parents for over four months, according to The Sunday Telegraph.
The paper reports that a pupil was given exam questions as home work in an email.
After sending her answers, mistakes were corrected with the instruction to learn them off by heart.
The results of all 18 French students were voided by the AQA, which offered an estimated mark and explained a teacher had offered improper assistance.
The teacher left Queen's Gate school voluntarily before the exam board's ruling.
The Duchess of Cornwall returns to her former school to visit pupils in west London
The Duchess of Cornwall attended the elite school in south Kensington, west London
It was only when a family grew concerned a school wasn't dealing with a remark request for their daughter's exam that the scandal surfaced.
The family in question spent more than £18,000 on legal costs after hiring lawyers to investigate.
Mrs Kamaryc eventually admitted to the family that the exam board had replaced their daughter's mark with an estimate after an investigation.
The mother told The Sunday Telegraph Mrs Kamaryc 'utterly betrayed" her daughter.
She accused the headmistress of seeking 'only to protect herself and the school'.
Celebrity chef Nigella Lawson also attended Queen's Gate School, whose headmistress is accused of a cover-up
'We feel completely betrayed,' she said. 'There was no loyalty shown to my daughter, let alone the hypocrisy of the head teacher, who tells pupils day in day out to be honest and truthful.'
Ofqual interviewed the family last week and is thought to be considering the incident in the context its wider investigation into exam malpractice.
The school admitted being told of a 'breach of security and improper assistance' from a teacher in July 2016.
It was notified results for two A-level French oral exams would be replaced with estimated marks.
The school claims to have immediately asked for clarification from the AQA.
It also says it asked for 'the possibility of re-marks for some candidates' and claims 'once the Board's final response was received the school wrote to parents'.
Students at Eton College, whose head of economics and politics, leaked exam details to pupils
Queen's Gate school denied misleading parents in The Sunday Telegraph.
'At all times, the school acted in good faith and in what we believed to be the best interests of pupils,' it said.
'The parents of the pupils who sat these examinations were notified at the earliest opportunity, once the Board had made its decision and once the school had as much information about the decision as the Board was willing to give to us.'
A school spokesperson said: 'We are now using External Examiners for these examinations, in order to ensure that there can be no repetition.
'The Board is very satisfied with the steps that the school has taken.'
An AQA spokesman said a thorough investigation was underway, adding it is standard practice to explain any estimated grades that result from malpractice investigations.
'Malpractice involving teachers is rare and the consequences are serious,' he said.
'Investigations have to be handled confidentially so we can't give details of cases, but we investigate all allegations thoroughly. '
When we find malpractice, we take action to make sure no one has an unfair advantage or disadvantage.'
Ofqual is thought to be considering the incident in the context of a wider investigation after malpractice was linked to other elite schools.
Charterhouse School in Surrey was also investigated but Cambridge International Examinations said there was no evidence of wrongdoing
Eton College and Winchester College leaked exam details to pupils, leading two disgraced scholars to leave their positions.
Mo Tanweer, head of Economics and Politics at Eton, was also one of the school's principal examiners.
The Cambridge graduate left his job after an investigation revealed he emailed three colleagues practice questions which 'breached exam security'.
Winchester College's Laurence Wolff is alleged to have given information on questions to be included in two papers.
Cambridge International Examinations board investigated Charterhouse School in Surrey over concerns it gave students advance warning about exam questions but said there was no evidence of wrongdoing by the school or its students.