Aylesbury Vale Academy is one of the worst performing schools in the country, according to new GCSE league tables published this week.
The figures show only 25% of pupils achieved five A* to C GCSEs including maths and English, down 15% on last year. It makes it the worst performing mainstream school in Bucks and the 21st worst in England.
However, principal Fiona Froment said the statistics are skewed because they do not take into account the results from English resits taken in November following the exam scandal in the summer which saw grade boundaries shifted without pupil or staff being aware.
She said once the resits are taken into account the actual percentage of students with five A* to Cs including English and maths is 38.5%.
Meanwhile, the league tables show that secondary modern (non-selective) school, Waddesdon CE, has continued to excel with 70% of its students recording five A* to Cs including maths and English.
However, the gulf between grammar schools and non-selective is still evident.
Aylesbury High School continues to lead the way in Bucks with all of its GCSE pupils achieving 5 A* to C grades including maths and English,.
Sir Henry Floyd Grammar School has for the first time in four years achieved more 5 A* to Cs than Aylesbury Grammar School with 99% of its students succeeding compared to the all-boys school’s 97%.
Elsewhere, 38% of The Mandeville School students got their 5 A* to Cs, an 5% increase on the previous year.
The John Colet achieved 51%; Cottesloe School, 51%; The Grange School, 49%; The Misbourne School, 54%; Princes Risborough, 49%.
A decision on whether English papers should be remarked is expected in the High Court this month.