A class full of students preparing for GCSE exams later this year must repeat coursework after concerns were raised about the amount of help the teenagers were given.
Hemel Hempstead School has launched an investigation and the Gazette believes the probe involves Year 11 students.
However, headteacher Patrick Harty is refusing to reveal the full details at this stage.
In a statement he said: “There have been concerns raised about the amount of guidance given to one of our classes of students as part of the curriculum.
“The education of our pupils is our primary concern and the school takes these matters seriously.
“It would be inappropriate to comment further while the school looks into this matter. We apologise for any inconvenience caused to pupils and parents.”
A letter sent out to the parents of affected children by the Heath Lane school’s head of English James Mitchell says: “As you may already be aware, as a result of recent internal moderation of GCSE folders in the English faculty, an error was found to have been made in the preparation and completion of your son/daughter’s controlled assessments.
“It is imperative that we are seen to work within the rules concerning the planning and completion of controlled assessments and, as such, the assessments must be completed anew in answer to different task titles/questions than was the case in the initial assessments.
“It is regrettable, but necessary, that the controlled assessments be repeated.”
In 2009 under government education reform controlled assessments replaced traditional coursework.
Instead, students now have to do the work in class under exam conditions.
Mr Mitchell told parents that: “It is at least a consolation that the error was detected in time such that the revision and planning necessary to support your son/daughter to re-attempt the assessments can take place.
“It may be a concern to you that some time has been wasted in the completion of the original assessments in what is a very busy academic year.
“It is true that the drafting process must be repeated.
“However, the controlled assessments are being written in response to texts already familiar to the students through previous study and so the content taught in previous lessons is relevant.”
He also encouraged parents to urge their children to take up extra sessions in preparation for the summer exams.
Has your child been affected? Let us know by calling 07803 505845.