A school described as “brilliant” by David Cameron was at the centre of an exam cheat probe yesterday.
Kingdale Foundation comprehensive is being investigated over allegations pupils were given answers to questions in GCSEs and A-levels.
Officials are also looking into claims that children were graded for coursework they had not completed.
Whistleblowers are thought to have called in watchdog Ofqual over tests taken earlier this year.
Hundreds of pupils now face an agonising wait for exam results–due out next month–as the probe could set them back weeks.
The row comes two months after the Prime Minister visited Kingdale, in Dulwich, south east London, and praised how it had turned itself around.
Yesterday the Department for Education said: “These are very serious allegations and they must be fully looked into.” Ofqual added: “We have been made aware of allegations of malpractice and are requiring the awarding organisations to keep us informed about the investigations which are now under way.”
Officials are probing whether pupils were helped in tests in English, maths and science. Representatives of three exam boards, including the prestigious Oxford Cambridge and RSA Examinations, have visited the school to quiz senior staff.
The school has been transformed from being judged as “poor” by inspectors 13 years ago to being rated “outstanding” by the government watchdog in its most recent report.
Last year Ofsted said: “The school is a magical place and makes dreams come true.”
Exam boards Edexcel, AQA and OCR are carrying out their own investigations. In the last set of GCSE results, more than 95% of pupils achieved the key national benchmark of five or more A* to C grades.
Headmaster Steve Morrison, who has been credited with turning the school around, said in a statement: “I am confident the school will be fully exonerated.”