High-tech cheating will spread across higher education unless the problem is tackled urgently, computer experts warned this week.
Last week's crisis at Edinburgh University - where grades for 90 students were withheld pending investigation - could be just the tip of the iceberg, they say.
Cutting and pasting material from web sites is now common practice and is a useful tool for students. The problem arises when they try to pass off downloaded material as their own work.
It is causing such concern that investigators have created a program universities can use to catch the cheats.
David Woolls of CFL Software in Birmingham said the integrity of university assessment was now under severe threat from "internet cheat sites" that have proliferated over the past three years and are notoriously difficult to police.
Mr Woolls is working with a forensic linguist from Birmingham University to investigate a number of charges of electronic plagiarism. He has concluded that the problem is growing across the sector.
He said: "Universities just aren't switched on to this. There is a huge educational programme needed for lecturers, many of whom are completely unaware of the scope of the internet for cheating, particularly in the arts and humanities, where its use is relatively new."
Mr Woolls said he knew of some institutions that had already turned away from assessed coursework and moved back to traditionally invigilated exams because this was the only way to guarantee that the work being marked was the student's own.
"The burden on lecturers is huge because to be sure not only would they need to be familiar with printed works but they would need to go to the web and check out every single internet site that could be relevant to each piece of work. Given the size of the web and the speed at which sites change, that task is virtually impossible," Mr Woolls said.
Malcolm Coulthard of Birmingham University's English department is working on a disputed case of electronic plagiarism in a university and has recently been contacted by 20 others with similar queries.
He said: "This is a very sensitive issue because no university wants to admit it has a problem with cheating. But the problem is obviously going to grow because it is so easy and students are very often more competent with computers than their staff."
Professor Coulthard and Mr Woolls have devised a program called CopyCatch that detects linguistic styles and can alert lecturers to plagiarised work.
It compares texts electronically by analysing similarities in vocabulary, phrase and sentence makeup.
Mr Woolls said: "Looking at independently produced texts on the same subject, we have discovered that coincidental overlap of lexical vocabulary in texts of between 500 and 2,000 words is commonly 30 to 40 per cent. Accordingly, anything above 70 per cent is highly indicative that texts share a substantial amount of material."
He added that universities were often reluctant to commit funds to guard against plagiarism, and yet a disputed case could easily run up bills of more than Pounds 10,000 once lawyers got involved.