Tens of thousands of GCSE and A-level coursework essays are available on the internet for pupils to copy and submit as their own.
A large number of study websites offer a variety of sample coursework essays. Study-Area.com, for example, offers students more than 1,200 sample essays, in a range of academic and vocational subjects. The site charges users pound;5 a month, or pound;15 a year.
But not all coursework sites charge pupils for access. Some, such as CourseworkHelp.co.uk, ask students to submit their own coursework essays in exchange for those that they view. But all offer essays on popular coursework topics.
Coursework.info, for example, provides 74 GCSE essays examining the Second World War. And biology candidates required to explain photosynthesis have more than 100 essays to choose from.
The aim, the websites insist, is not to assist would-be plagiarists.
Instead, it is to provide pupils with useful guidance for their own work.
"Reading other students' material can help clarify ideas, eliminate a mental block, provide ideas on how to structure your own piece of work, and provide a succinct overview on a subject," the Study-Area website says.
John Wilkes, past examiner for English GCSE coursework, and London secretary of the National Association for the Teaching of English, says teachers are aware of these sites, and are starting to tailor assignments accordingly.
"In the past, we asked students to write about the role of the inspector in the play, An Inspector Calls. Now we'll choose a particular section of the play.
"The more you narrow the focus down, the harder it is for students to find something relevant. You just have to keep ahead of the game."
The websites themselves offer warnings about the dangers of plagiarism.
Revise.it tells would-be coursework cheats: "You risk being disqualified from all your public exams."
Many websites insert irrelevant or nonsensical phrases into their essays, in order to betray pupils who not only submit someone else's essay, but fail to read it first. Essaybank.co.uk makes the teachers' task even easier: the website's name is inserted into its essays.
But, says Mr Wilkes, most teachers can identify fraudulent coursework without this assistance: "If pupils submit a piece of work unlike anything they've done before, it's bound to be spotted."
Teachers are required to sign a statement affirming that coursework is a student's own, and exam board assessors are alert for batches of essay scripts containing identical phrases.
Plagiarism is not a problem unique to the electronic age. Olwyn Gunn, education spokesperson for the National Association of Schoolmasters Union of Women Teachers, said: "There have always been opportunities for pupils to access information. In the past, they went to libraries and found books.
It just happens to be much easier now."