Universities have raised almost £50m from fining students for overdue library books in the past six years.

Leeds University accrued the most money from overdue books, collecting more than £1.8m in fines for the six academic years from 2004/05.

Manchester University, which collected almost £1.3m, came in second place while the University of Wolverhampton was third with fines totalling £1.25m.

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. But many are never returned – more than 300,000 university library books remain unaccounted for.

Bucks New University has the most missing books – 30,540, followed closely by Oxford University with 20,923 and the University of Kent with 19,613.

The figures were revealed in freedom of information requests to all of Britain's universities by the Press Association. In total, 101 universities responded to the request, although many were unable to provide details of the amounts they fined students for late library loans.

Most students are fined 10p for every day a book is overdue, but those at at Edinburgh Napier University can be charged up to £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 said.

Persistent offenders can have their library account suspended or lose access to their university's IT system.

At Imperial College London an outstanding £4 fine will lead to library privileges being revoked until the books are returned.

The University of Westminster does not fine students for returning library books late. Students are instead banned from using the library for the length of time that the books were overdue.

Many universities bar students from graduating until they pay their fines.

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:

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