The film is loosely based on a biography of the same age

He claims Nash admitted he never made a total recovery from his illness and Hollywood is trying to turn his life story into an unconditional triumph.

Taylor, who reviews films for Salon.com, says: "It's been conceived as something to make audiences weep and to win Oscars."

'Love conquers all'

The New York Times critic who praised certain aspects of A Beautiful Mind also found that the story was "almost entirely counterfeit."

Other reviewers complained Nash's recovery from schizophrenia was presented too much in terms of a "love conquers all" narrative.

In defending their picture, the film-makers insist A Beautiful Mind is not a biography, but a human drama "inspired" by events in John Nash's life.

Jennifer Connelly plays Alicia Nash

Director Ron Howard says: "It is very true in terms of his life. It's not his complete life.

"All the scenes are not the absolute words that John Nash said, but then again, the sweep of his life, the architecture of his life, is very true to what he and his wife Alicia have dealt with."

But critics say it airbrushes away certain uncomfortable realities.

Nash and his wife divorced, before remarrying last year, but this is never mentioned in the film.

Neither is the fact that he Nash fathered a child with another woman and then reportedly abandoned them both.

Also Nash was arrested in the 1950's for soliciting sex in a men's public lavatory, and also had a number of apparently sexual liaisons with men, but these details too have been omitted.

'Not relevant'

Screenwriter Akiva Goldsman maintains all these aspects of Nash's life were left out because they just weren't relevant to the basic thrust of the screenplay.

Goldsman says, "John did or didn't have sexual relationships with men. According to John, he didn't.

Crowe won a Golden Globe for his role

"But in any case, it wasn't what the story was about. John also had a wife, a long relationship with another woman and another son. All these incidents occurred outside the context of the story that we're telling.

"Our story is about one abiding relationship - John and Alicia - and the way that relationship carried him through his journey to healing."

Syliva Nasar, who wrote the biography on which the film is partly based, thinks much of the criticism misses the point.

She believes the picture presents a valuable and realistic portrait of schizophrenia that is rarely seen.

Nasar says: "This is the first time someone with this illness not only survives it, and triumphs over it but is seen as a fully multi-dimensional human being who's loved. That's amazing.

"I think anyone who knows, either through personal experience or otherwise, about this illness that is what's amazing about the movie."

Nasar does not stand alone in this assessment because many mental health professionals have confirmed the film gives a very accurate portrayal of a person suffering from paranoid schizophrenia.

But critic Charles Taylor says that alone "doesn't make it a good movie".

"Movies are not public service announcements. If you're saying 'I'm going to go and present a positive image of mental illness,' you're really in the advertising business," he says.

Defending the film: Producer Brian Grazer and Ron Howard

'Jeopardy'

In previous years similar films which have had the veracity of their storytelling challenged have found the negative criticism jeopardised their Oscar chances.

But this seems unlikely to happen with A Beautiful Mind. John Nash has seen the film and, according to his biographer, really likes it.

The picture also has many admirers who believe the essential truth of Nash's story has been preserved.

Russell Crowe and Jennifer Connelly's acting has been widely praised and won significant pre-Oscar awards.

Akiva Goldsman's ingenious screenplay has its fans, as well as detractors.

Finally, everyone seems to think that Ron Howard's time has come.

The Oscars ceremony will be broadcast live on BBC Two on Monday 25 March from 0045-0600 GMT and reported live on BBC News Online.