On only a few occasions, says London mum Alice Breese, did she help her teenagers cheat in their exams. Once, one of her four children “reached a complete standstill” while writing a coursework essay for English A-level. “He froze. I wrote a potential introduction on the computer to kick-start him. And he used it,” she says.

Another time her daughter was “stuck” on history coursework so Breese suggested she should base her essay on one her brother had written on the same subject two years earlier — which their mum knew had already been awarded an A grade.

Both times, Breese knew — just like thousands of parents across the country — she was “breaking the rules” on coursework, an essay or project which many schools allow children to work on at home even though it makes up a quarter of the marks at GCSE level.

Breese felt uncomfortable about her actions — though she was never “found out” — but takes comfort from the fact that she “helped” far less than many of her friends. “I know parents who did all the work, delivering it ready in a folder into the child’s hand,” she says.

There can be no doubt that cheating in GCSE and A-level exams is on the rise. Even though many culprits escape detection, figures from the five exam boards show that 3,600 teenagers were caught breaking the rules last year — 9% up on the year before.

As well as “collusion” over coursework (695 cases), offences included taking mobile phones, books or notes into the exam room and plagiarism — “lifting” material, often from the internet and pasting it into essays and projects.

But it’s coursework that poses the greatest temptations. “Cheating in coursework is getting worse and worse,” says Anthony Seldon, the new head at Wellington college. “Coursework is a complete farce.”

Even teachers, under pressure to get good exam results, are exposed to the risks. In May Prince Harry’s art teacher at Eton, Sarah Forsyth, claimed that she was ordered to compile part of his written coursework (though the exam board later decided there was no evidence of improper behaviour).

Teachers who mark coursework have also been accused of being overgenerous — of awarding A grades, for instance, for work that’s only worth a B. When such a trend is spotted, an entire class’s results can be downgraded — but since external examiners check only a sample of scripts there might be a lot of overinflated marks slipping through the net.

The situation has become so bad that the exam watchdog, the Qualifications and Curriculum Authority, (QCA) will later this year publish the results of a two-year investigation into coursework — as well as new rules to crack down on cheats.

As part of the QCA inquiry children who had just finished their exams were asked to answer a confidential survey spilling the beans on how much “help” they had had. This gave the regulators a snapshot of how widespread exam fraud is nationwide.

“The big issue for us is — are parents helping children with their coursework?” explains a spokesman at the QCA. “We don’t necessarily want to stop it. We do want parents to get involved in their children’s education but we need to clarify the extent of help parents can give so parents are not actually doing their children’s work, just assisting their research.”

So where exactly will the boundaries be drawn? The spokesman says there will be a lot of detail in the report but the general rule for parents is: don’t put pen to paper (or fingers to keyboard). “Parents helping with coursework is not cheating,” he says. “Parents writing coursework is cheating. They can help children with research, guiding them in the right direction. But they must not be writing the work.”