Private tutors have told The TES that they are being approached every week by students asking them to write their GCSE andA-level coursework.
Tutors say they routinely get requests for help, sometimes from existing students and sometimes through telephone calls from pupils they have not met.
Alan Barnard, principal of West Midlands-based Cloisters Tutoring and Educational Services, which has worked with 14,000 pupils in the past 11 years, said: "The problem is gross. People ring up every week asking us if we will do their coursework and pop it in the post.
"Recently a pupil wanted 'help' with history coursework. You ask them how far they've got with it and they say they haven't started. That's usually a good clue that they want more than tutoring.
"Mostly the requests are for English and history coursework. They have months to work on it. But of course a lot of them don't. Then we get a call to say the deadline is next Thursday, can we help? It puts the tutor in an awkward position."
Tom Maher, co-ordinator of British Home Tutors, based in Fulham, west London, said: "Requests are coming in all the time. It happens a few times a month. AQA economics, for example, has a big coursework component. We are asked, 'can you help me with this?'
"Sometimes you have students who are not that great. They are supposed to come in with a draft and they come back with a blank sheet of paper. They have not got anything down and ask if you can help them start."
Four other agencies - Personal Tutors, County Tutors, Osborne Cawkwell Education Consultants and Professional Home Tutors- all had experience of students asking for help with coursework.
"Helping" students is a grey area. Teachers are allowed to give students advice, but all the agencies said they drew the line at act-ually drafting work for tutees.
But Mr Maher thought some tutors were doing this. He said he knew of one company that had written an essay for a student which had been submitted to support an Oxford entry exam.
Some parents thought they could buy whatever help their students needed.
"Education is meant to be about merit, and helping people fulfil their potential, but these people are treating it like a commodity that can be purchased," he said.
The claims are the latest to hit coursework and follow criticism earlier this year from teachers that schools are allowing pupils multiple "redrafts" of work to boost league table positions.
Several websites also offer students the chance to download essays.
However, the Qualifications and Curriculum Authority could give no details of any action it could take against these sites.
The Government's taskforce on secondary education is proposing that all students complete an extended cross-curricular research project, rather than coursework in each subject, as part of a baccalaureate-style diploma for schoolleavers.
Mr Maher said this should not go ahead unless the Government could guarantee that all the work would be the student's own.
A spokesman for the Qualifications and Curriculum Authority said that teachers assessing coursework were required to take steps to satisfy themselves that the work was the pupil's own.
He added: "In the rare instances where there are allegations of malpractice, these are investigated thoroughly. Any student caught cheating risks being disqualified."
This summer, a student from a school in Wales, who cut-and-pasted information from an American website into an AS-level psychology coursework essay, had the grades from that module annulled. But the Edexcel exam board decided not to disqualify him and he was allowed to resit the module.
A Government spokeswoman said that exam bodies also provided external moderators to check coursework. She added: "There's no evidence of widespread cheating at GCSE or A-level."
Requirements for tutors
* The Association of Tutors estimates there are 50,000 full and part-time private coaches working in the UK.
* Fees range from about pound;15 to pound;100 an hour.
* Tutors do not need a teaching qualification, but most tutoring agencies require at least a degree in the subject to be taught and an enhanced criminal record certificate.
* The certificate shows all spent and unspent convictions, cautions, and details of any involvement in police investigations, even those that did not lead to prosecution or police action.
Association of Tutors: 01604 624171 www.tutor.co.uk