In life John Osborne was full of fury. His writing brimmed with vitriol and his first great stage hit, Look Back In Anger, inspired a whole literary generation of 'angry young men'. 'Anger is good,' he once declared.

Now, six years after the playwright's death, his work is once again at the centre of a storm of resentment. Osborne's widow, Helen, has received a 'bizarre and unfeeling' letter from her late husband's publishers, Faber and Faber, which has astonished her and many of the playwright's oldest friends.

The letter, from managing director Tony Faber, requested repayment of the full figure of the advance - £20,000 - that Osborne had been paid for the third volume of his autobiography.

'As part of a general review exercise,' the letter read, 'we have been going through the outstanding advances on undelivered titles. According to our records, Autobiography Vol. III Young Men Forget by John Osborne falls into this category.'

The first two volumes of Osborne's autobiography, A Better Class of Person and Almost A Gentleman, were published in 1981 and 1991, respectively. The third volume was under way, and the notes the author had prepared for it during his final illness are now kept at the University of Texas.

By taking action to recover the money in the last few months of 2000, the publisher appears to have hoped to act before a six-year cut-off point for repayment. As far as Mrs Osborne is concerned, it has also conveniently forgotten the internationally renowned work, including the plays The Entertainer, Inadmissible Evidence and A Patriot For Me, which it has benefited from publishing.

'He seems to be being penalised for dying,' the theatre director Richard Eyre said. 'They should remember that at one time he was certainly a major earner for Faber.'

Mrs Osborne's outrage has been shared by several of her husband's former friends and fellow writers, including the playwrights Harold Pinter and David Hare. She has also been advised by the theatrical impresario Robert Fox, brother of the actors James and Edward. 'We are still hoping that this can be resolved,' Fox told The Observer. 'I believe they may be meeting to discuss it this week.'

Mrs Osborne is trying to organise the repayment in instalments, but is believed to have been badly shaken by Faber's insistence. The Shropshire home she shared with the playwright during his final years has already been handed over to a charitable trust and his literary estate is now bankrupt.

Towards the end of last year, she telephoned Faber to argue that the contract had simply been terminated, or 'frustrated', by her husband's death. She explained that 'it seems a bizarre and unfeeling interpretation to wait until a few scant weeks before his deadline to raise the matter for the first time'.

Faber told The Observer he believed the matter could be resolved and he had suggested Mrs Osborne repay a proportion of the sum through deductions to royalties. 'It is simply not a sum we can afford to ignore,' he said.

Adrian Laing, a legal expert at HarperCollins, said that contracts with authors usually carried a clause covering the conditions for repayment of an advance in the case of non-completion.

'It is an unusual situation but sometimes amounts can be deducted from the advance and another writer can be hired to complete the work,' he said.

Fourth Estate is facing a similar problem. The firm had a six-figure deal with the QC George Carman and, after Carman's death earlier this year before the promised autobiography had been written, is now in negotiations with his son, the publisher Dominic Carman.

Osborne led a turbulent life and by the time he died he had been in financial difficulties for some years. In spite of his series of award-winning plays and the screenwriting prowess that was evident in Tony Richardson's 1963 film Tom Jones, for which Osborne won an Oscar, the couple ran out of money.

When Look Back In Anger, starring Alan Bates, Mary Ure and Kenneth Haigh, was first produced at George Devine's experimental Royal Court Theatre in 1956, Osborne was hailed as the brightest new talent in the country. The play gave birth to a whole new vocabulary and its central character, Jimmy Porter, became the archetypal 'anti-hero' of the age.

The impact of the play was marked by Kenneth Tynan's review in this newspaper; he famously said he could never love someone who did not want to see Look Back In Anger. He added, in words that are now particularly pertinent, that underneath all the nasty invective in the play was 'the determination that no one who dies shall go unmourned'.

The playwright married five times - to Pamela Lane, actress Mary Ure, Penelope Gilliat, by whom he had a daughter, Nolan, actress Jill Bennett, and Helen.

Osborne's official biographer, John Halpern, said he would have loved to have read the third volume of the playwright's own memoirs. 'But he died. And I don't think anyone should hold that against him. Especially not the publishers he had been with for so long.'