A prestigious private girls’ school has apologised after a group of students taking the English Literature International GCSE exam opened their papers to discover they had been taught the wrong book.

Malvern St James Girls’ School, a boarding school in Worcestershire, has launched an investigation into the incident after students found out the text they had been studying for years was incorrect, .

One parent, who wished to remain anonymous, said her daughter had been left “stressed out” by the incident. It could “scar students for life. It has been a complete utter waste of time for two years”, she warned.

The teenager had been studying Spies by Michael Frayn alongside her classmates for the International GCSE (IGCSE) exam - but when she opened the paper, she discovered there were no questions related to the text.

Speaking to The Independent, the parent said she had lost faith in the fee-paying school and added “for that amount of money they should not be making mistakes."

She said: “I want compensation and I want heads to roll. You have to be responsible of what your teachers are doing. For two years they have been studying the wrong book. It is a joke."

Malvern St James Girls’ School confirmed that one of texts taught to a group of Year 11 students for their IGCSE English Literature paper on Wednesday morning had been “incorrect”.

“The problem was identified immediately, and we are now working with the exam board in question, so that no girl should be disadvantaged by this.Fortunately, all exam boards have procedures in place to deal with this type of incident and we meet the criteria for ‘special consideration. “We apologise wholeheartedly for this, and will continue to work to resolve this issue as soon as possible,” said Olivera Raraty, headmistress of Malvern St James Girls’ School.

It is unclear at this stage how many pupils were affected by the mistake at the school - which has been rated as 'excellent' by the Independent Schools Inspectorate.

Alumni of the 400-pupil school, where fees are up to 50,000$ a year, include Green Party MP for Brighton Pavilion Caroline Lucas and the Duke of Gloucester's mother Princess Alice.

The private school has approached the exam board, Cambridge International, for “special consideration” to be made for the students affected by the school’s error.

“We were contacted by the school today as they discovered they had taught the wrong English Literature text. We recognise that this is distressing for the students involved. We have asked the school to follow our procedures for rare situations like this by submitting a request for special consideration on behalf of the students affected,” said a spokesperson for exam board Cambridge International