Universities have raised nearly £50 million from fining students for overdue library books, figures have revealed.
Top of the pile was Leeds University, which has raised more than £1.8 million in the last six years.
In second place was Manchester University, which collected almost £1.3 million and in third was the University of Wolverhampton with £1.25 million.
At the bottom of the table was Imperial College London, which collected just £26,703 in fines.
With fines as little as 10p for each day a book is overdue, it shows that students are returning thousands of books late each year.
However, many are never returned at all as more than 300,000 books remain unaccounted for from universities across the country.
Leading the way at number one was Bucks New University with 30,540, closely followed by Oxford University with 20,923 and the University of Kent with 19,613.
In order to avoid paying the full price to their university for a new copy, some students are turning to the internet and buying replacements from Amazon.
The figures were revealed in Freedom of Information requests to all of Britain's universities by the Press Association.
They to supply details of the amount of fines issued, the total received and the number of books unaccounted for from its libraries for the six academic years from 2004/05.
In total 101 universities responded to the request but many were unable to provide details of the amounts they fined students for returning books late.
Penalties at the universities vary.
Most students are fined 10p for every day a book is overdue, while at Edinburgh Napier University daily fines can be as much as £1 per day.
"The charge on the invoice reflects the amount it would cost us to replace the item using our normal suppliers," the university revealed in replying to the FOI request.
"Sometimes a student who has genuinely lost an item will buy it through Amazon at a reduced price and give us the book - we are very happy to accept that.
"At the end of the day our priority is to ensure that materials we have in stock for student use are available so when an item is not returned we start the invoice process with the aim of replacing the item."
For persistent offending, students can have their library account suspended or lose access to their university's IT system.
At Imperial College London an outstanding fine of £4 will see library privileges barred until the books are returned.
Aston University admitted that some students get around a library suspension by getting their friends to borrow books on their behalf.
"Beyond the limit of 15, borrowing is stopped until the fine is paid - although we know that in some cases students simply ask their friends to borrow for them to avoid paying the fines," the university's reply to the FOI request reveals.
The odd one out was the University of Westminster, which does not fine students at all for returning library books late.
Instead of a financial penalty, students are banned from using the library for the length of time that corresponds with how late their books are.
Some may even be barred from graduating if they owe their university money.
As little as a £5 debt at Exeter University will prevent graduation, as will £20 at Lancaster University or £25 at the University of Glasgow.
Other universities said they would instruct debt collection agencies if the library debts were part of other larger debts owed, such as fees and accommodation.
The top 10 universities raising the most in library fines were:
:: University of Leeds - 1,869,340
:: University of Manchester - 1,299,342
:: University of Wolverhampton - 1,252,253
:: King's College London - 1,197,715
:: University of Hertfordshire - 1,147,238
:: University of Birmingham - 1,114,863
:: University of Plymouth - 1,058,777
:: University of Nottingham - 1,025,560
:: Kingston University - 1,020,753
:: University of Durham - 1,005,426
The top 10 universities with the most unaccounted for library books were:
:: Bucks New University - 30,540
:: University of Oxford - 20,923
:: University of Kent - 19,613
:: University of Sunderland - 17,650
:: University of Teesside - 15,815
:: Brunel University - 10,992
:: London South Bank - 9,725
:: London South Bank University - 9,725
:: University of Greenwich - 8,580
:: Southampton Solent University - 6,126