Students at Bradford University have been warned not to sell their assignments to an internet organisation because doing so will breach academic regulations and copyright laws, writes Jennifer Currie.
Notices advertising tsar.com's services were removed from the campus after university officials realised what they were offering.
Nick Andrew, Bradford's registrar and secretary, said students had to be reminded to act responsibly.
"If they are caught buying essays from the internet then it is plagiarism, and if they sell them, then they are aiding and abetting other plagiarists."
Students face disciplinary action if they substitute work taken from internet sites for their own.
"This is a problem facing the sector as a whole. If we respond to it prudently it will present no threat. But it is already causing some anxiety," Mr Andrew said.
The National Union of Students has also advised students not to use the internet to cheat.
An NUS spokesperson said: "Students work hard for the credit they get from academia and lecturers work hard to accredit them.
"Anyone involved in these websites is involved in a deception that abuses the sector's trust and insults the hard-working people in it."
However, the lack of internet law in this country means that students are free to sell their work for others to use.
Philip Leith, reader in law at Queen's University, Belfast said: "I can't see that students are doing anything illegal in selling their essays or that anyone apart from the student has copyright in them.
"As long as they assign their copyright to the company, that company can do what it wants with them. However, students who purchase them will be in breach of their university regulations if they use them as examples of their own work."
Independent studies have suggested that universities need to revamp assessment structures to eliminate banks of recycled essay questions that require generic, easily copied answers.
"We need to make it difficult for plagiarists to operate," Mr Andrew said.
"The most amazing thing about this case is that it is remarkably unsubtle. You don't see people advertising when they are going to rob a bank, do you?"