Tens of thousands of students in universities across Britain have been caught cheating in exams and coursework – and the trend is on the rise, according to a investigation by The Independent on Sunday.

Over the past three years, more than 45,000 students at 80 institutions have been hauled before college authorities and found guilty of "academic misconduct" ranging from bringing crib-sheets or mobile phones into exams to paying private firms to write essays for them.

Some 16,000 cases were recorded in the past year alone, as university chiefs spent millions on software to identify work reproduced from published material, or simply cut and pasted from the internet.

But officials last night warned they were fighting a losing battle against hi-tech advances – which means it is becoming increasingly difficult to detect the cheats.

Tessa Byars, an advice services manager at Anglia Ruskin University Students' Union, warned that advances in technology had made it "nearly impossible" for universities to keep up.

"It's only going to get worse," she said. "From next September we expect to see cheating incidents rise. The introduction of tuition fees will increase pressure and anxiety to get a good degree. They're all worried about their employment prospects."

University bosses blame the financial crisis for raising the stakes in higher education, making many students willing to do anything to secure good grades – or just to stay on their degree courses. A number of experts claim that Tony Blair's flagship policy of increasing access to higher education has left thousands of young people starting university without all the practical and intellectual skills required.

Ministers have now been urged to step in to help institutions defend standards against increasingly sophisticated methods, particularly agencies that produce customised essays for students – often for fees of hundreds of pounds.

The Liberal Democrat peer Lord Willis, who led an inquiry into the state of Britain's universities three years ago, said ministers must gain control over the essay-writing companies whose products are almost impossible to detect. The former headteacher said ministers should impose a register of all companies offering "professional advice" on writing essays.

Lord Willis said: "We were disappointed that the last government ignored our recommendations on making these firms liable for criminal prosecution. Something needs to be done to bring them into line."

Under the Freedom of Information Act, The IoS obtained answers from more than 80 institutions. The responses revealed a catalogue of offences, including individuals caught taking exams for someone else, using concealed notes or taking mobile phones into examination halls and "colluding" with fellow students to produce identical coursework.

Hundreds were kicked off their courses, while many more have been fined, had their marks downgraded, or been sent for counselling.

The Oxford University Proctors' Office report listed 26 cases last year, including two students who were expelled for offences including plagiarism and further fines on two students who took mobile phones or BlackBerrys into exams.

The IoS has established that at least 45,000 students at more than 80 UK institutions have been hauled before the authorities and found guilty of misconduct in their exams or coursework over the past three years. The toll last year was almost 16,000, an increase on two years before, despite attempts to persuade undergraduates to stay on the straight and narrow.

Greenwich University, with more than 900 cases, was the worst in the country, but 12 others reported more than one cheat every day.

The high rate of cheating has also been blamed in part on the tens of thousands of international students who, Ms Byars said, "come from countries with different practices and cultures". Others said the recent huge increase in undergraduates meant there were many students at "new universities" who were not adequately prepared to complete degrees.

Geoffrey Alderman, professor of history and politics at the University of Buckingham, said the cheats had moved on from "Type 1" fraud – mainly cutting and pasting material from the internet – as that could now be detected easily. Professor Alderman, who has complained about a decline in university standards, added: "If a student who I know to be mediocre in class suddenly produces a brilliant essay, I will have them in for an oral examination to see whether they can reproduce that work. I'm not sure all universities do that. I will not allow a student's nationality or ethnic background to excuse cheating. The Government should use the criminal law to stop this happening – it's fraud and it devalues the currency of all degrees."

Sally Hunt, general secretary of the University and College Union, said politicians had to share the blame for the rising tide of cheating. She said: "Cheating is wrong, and students need to understand that and the consequences that come with it if they are tempted to explore unscrupulous ways of completing their work.

"However, successive governments are also partly to blame. Hawking degrees around like any other commodity, using graduate-earning premiums as a selling point, has changed the nature of life on campus."

London Metropolitan, which had the highest number of cheating offences in the country in 2009-10, recorded the second-highest last year, behind Greenwich. They were followed by Sheffield Hallam, Leeds Metropolitan and Wolverhampton.

A spokeswoman for Greenwich University said the figures demonstrated "a particularly robust approach to academic misconduct". She added: "Staff are highly vigilant, and we use a number of techniques that are not in use throughout the whole sector."

Increasingly, universities are taking a defensive stance – insisting it is complicated by a growing number of students who enter university unfamiliar with the correct procedures of citation or who do not have a good command of English.

Niall Hayes, a lecturer at Lancaster University Management School, said: "People come to us without experience of extended writing or formulating arguments and building on other's ideas. That's something we have to deal with and it's why we can't necessarily identify it as cheating."

Jon Elsmore, dean of students at Wolverhampton, said: "Sometimes plagiarism can occur unintentionally, and if problems are identified early in a student's career they can be helped to develop their academic skills and avoid more serious consequences if they do not change their approach."

Essays to order: The IoS road test

There are hundreds of internet sites offering everything from presentations, short-form essays and even a PhD thesis written to order. Some are based in the UK while many exist only online.

Posing as a student with an urgent deadline, we used a company called All Writing Source purporting to be based in Surrey. Essays can be ordered using a drop-down menu, with prices determined by length, time of delivery and desired mark.

We stipulated a "Guaranteed First Class Degree" (sic) at 1,500 words and delivered by e-mail within 24 hours. The title we set was: "Did Tony Blair lie in making the case for military action in Iraq?"

The total cost came in at £143.70. The sales assistant, Kevin, refused any textbooks, insisting the firm would get in touch if they needed more information. "The reason is that we have our own in-house writers who do the job for us... free from all plagiarisms," he wrote. He promised to deliver the essay in under 24 hours.

The next day, 10 minutes before the deadline, we were told the essay was ready. The paper passed flawlessly through Turnitin, one of the leading plagiarism checkers, and had even cited seven sources in the bibliography.

But was it really the "Guaranteed First Class" that we were promised?

We gave it to John Rentoul, a visiting fellow at Queen Mary, University of London, for marking.

Professor Rentoul's verdict: "Some evidence of knowledge of the subject, but:

1. Very poor grammar and style, unintelligible in places (reads as if it has been translated by Google from another language);

2. Very poor sources and sourcing. All four books cited are polemical anti-war works. No primary material cited at all;

3. Argument, analysis and narrative weak and unsupported by evidence. Much too polemical rather than historical in style. The question needs to be defined and then the evidence for and against needs to be cited and weighed.

Please see me for further advice." Mark: 42 (Third Class marks: 40-49)

We returned to the company the next day, explaining that we were from The Independent on Sunday. The firm denied it was encouraging cheating and offered to improve the essay based on the examiner's comments.

The company's website disclaimer reads: "AllWritingSource.co.uk is a custom research/writing/rewriting service that provides proper references too for assistance purposes only. It is necessary to use every paper with appropriate reference. The papers provided serve as model papers for students and are not to be submitted as it is. These papers are intended to be used for research and reference purposes only."

Case studies...

Regretful and reformed

Ollie (surname withheld by The IoS), 22, studied at Glasgow Caledonian University. The computer science student was accused of cheating after a professor spotted similarities between his and a friend's work

"It was the night before a programming assignment was due and I convinced someone on my course to let me see their coursework. I tried to change some details and I thought it would be enough. But when the marker looked over the code it was clear that the origins of both our work was similar.

"We were called in on separate occasions to explain the code outline, how it worked, in order to try to work out which of us was cheating. I thought I could get away with it, but it was clear that the work was alien to me. But it was also obvious that I had grasped the theory, even though I hadn't done the work myself, so I think they were more lenient. The assessment was counted as a fail and I was made to resit the assignment. In the end, I took the blame. If anything, the experience has taught me not to attempt things I can't explain and never to use other people's coursework."

The accused

Clare Trayner, 23, was a geography student at Royal Holloway who was accused of cheating after anti-plagiarism software flagged up her essay

"Everyone was emailed to collect their essay, but mine was held back. I was then told to attend a formal meeting as I had been caught committing plagiarism. I knew I hadn't cheated but I wasn't clear on what the problem was.

"I was told one paragraph had been flagged up as resembling the content on an internet site. Eventually I was found guilty of plagiarism but as it was my first time I would be only marked down by 10 per cent on that module. My mark for the module went from a high 2:1 to a 2:2."