John Schlesinger, the Oscar-winning director of Billy Liar and Midnight Cowboy, blamed Madonna's "outrageous" behaviour on the set of a film they were making for contributing to his heart attack.

His damning comments about the pop singer turned actress are contained in a collection of letters and production notes bequeathed to the British Film Institute by the veteran film-maker after his death in July 2003.

The papers reveal that Schlesinger, who worked with Madonna in 1999 on his last film, The Next Best Thing (released in 2000), became enraged by her attempts to change numerous scenes. They also show that Madonna demanded that special effects be used to "beautify" her appearance.

In the film, a comedy, Madonna plays a yoga instructor who becomes pregnant after a drunken one-night stand with her homosexual best friend, played by Rupert Everett.

Shortly after completing what was one of the unhappiest shoots of his career, Schlesinger, then 73, collapsed on the doorstep of his London home. He was diagnosed with heart failure and underwent a quadruple heart bypass operation.

His workload before he was admitted to hospital had been particularly heavy and he had complained of being "exhausted" before he left Los Angeles at the end of the film shoot.

In a letter written from the Royal Brompton Hospital on December 2, 1999, to Andrew Cannava, his agent, however, Schlesinger put some of the blame for his collapse on Madonna's collaboration with Tom Rosenberg, the film's producer, to change the film.

"I am f***ing angry with Tom being influenced by Madonna," Schlesinger wrote. "We have tried all of these changes before . . . I do not for one moment think that their behaviour has not added to the reasons I have ended up here."

His letters, along with his production notes, complain that Madonna tried to influence every aspect of the production, from the music to the final cut.

One unsigned memo suggests that the actress, then 41, wanted producers to "beautify" 34 shots of her with computer generated imagery, the special effects technique pioneered in fantasy epics such as Jurassic Park and Titanic. It appears that the money was eventually found to improve just nine of the scenes.

Surprisingly, the singer, who appeared naked in her controversial 1992 book Sex, also balked at the idea of appearing fully nude in the film. An unsigned memo which relates to production meetings held in 1998 states: "Madonna doesn't want her bare arse to be seen."

Later, Madonna lobbied for the removal of a pivotal scene which she felt was too "gay", much to the disgust of Schlesinger, who was himself homosexual.

These constant demands infuriated the director, who had previously worked with such actors as Lord Olivier, Dustin Hoffman and Glenda Jackson. In a letter to Mr Rosenberg on November 30, 1999, dictated from his hospital bed, he wrote: "I am outraged that Madonna is starting to express an opinion of what works and what doesn't and what is too gay when she wasn't even present at the previews. In any case, she is not the director; so far as I am concerned I want the scene to remain as it is."

He also complained to Sherry Lansing, the head of Paramount, saying: "I am lying here feeling very frustrated because the completion of the film is taking place without me and it seems to me that Tom Rosenberg is very much listening to Madonna's opinion, which is affecting the cut and the choice of music."

One handwritten six-page letter from Madonna, who was also executive producer of the film's soundtrack, to Schlesinger in July 1999 reveals that she lobbied hard for the inclusion of particular kinds of music in the film itself.

She claims that she does "not mean to be presumptuous" or to "overstep the bounds", before outlining the case for more Indian- influenced music in the film. After reminding the director that she does have a "lot of experience" in the field of film scores, she urges him to listen to a selection of tracks that she has put on a CD.

"Even if you don't like the music perhaps it will inspire you and get your gears going . . . Please listen in a quiet place with no interruptions. Turn off the phone, light a candle and think about the love story of Robert and Abbie and their world and sadness and the hope. Enjoy. I hope to hear from you soon." She signs off: "All My Love, M xxx."

The Next Best Thing, which cost $25 million (£13.5 million) to make, was a commercial and artistic disaster, taking just $23 million worldwide. Madonna's performance was savaged by critics and earned her a "Golden Raspberry" award for worst actress. Entertainment Weekly said that she could "barely muster even the rudiments of human expression" and urged her to "quit while she is behind".

Schlesinger was discharged from hospital in January, 2000. The following December he suffered a debilitating stroke. His condition grew steadily worse until he was admitted to hospital in Palm Springs last July. He died a year ago, aged 77.

Liz Rosenberg, Madonna's publicist, said last week that she was surprised by Mr Schlesinger's remarks: "People say many, many things about Madonna but no one has ever questioned her level of professional behaviour. I know Madonna had great respect for John Schlesinger as a director. I believe that John Schlesinger had control over this film and Madonna behaved as a salaried actress."

A spokesman for Mr Rosenberg said that the producer had found it an "honour to work with Mr Schlesinger who he had considered to be one of the greatest directors in the history of the movie business".