New research by a leading British historian has cast serious doubt on its fundamental proposition: that the Austrian-born queen's sexual indiscretions precipitated the 1789 revolution which delivered her to her fate at la guillotine.

Simon Burrows, of Leeds University, has uncovered evidence that the salacious pamphlets which revealed the queen had been promiscuous with lovers of both sexes were not distributed until after the revolution had started - a finding that dispels the so-called "pornographic" interpretation of the French Revolution.

One of the more vindictive allegations made in the pamphlets, many of which were produced in London, was that Marie Antoinette slept with her brother-in-law, Charles, Comte d'Artois. That was a mere frippery compared to the allegation aired at the queen's trial in 1793 that she had molested her own son while in prison. Claims about the queen's lesbianism were started by Comtesse de La Motte, who famously attempted to trick the queen out of money by procuring a diamond necklace in her name. She described in a "memoir" their frequent assignations, which involved shared "momens d'ivresse que j'ose à peine retracer" ("moments of delirium that I can scarcely dare recall").

But this and other libelles, as the writings are known, were kept away from the French population by royal agents who bought and destroyed them, Dr Burrows reveals in his book, Blackmail, scandal and revolution, to be published next month. A few copies of the libelles were kept in a depot in the Bastille, where they were not discovered until it was stormed on 14 July 1789.

Historical records provide little - if any - evidence of the sexual promiscuity described in the pamphlets, which Coppola draws on. "There is no evidence that she had any lovers at all," said Dr Burrows. "There is a question about her emotional attachment to Axel von Fersen, the Swedish aristocrat, but little more."

Historians are even divided over the dashing Fersen, who risked his life many times to free the queen. Lady Antonia Fraser, on whose much respected 2001 biography, Marie Antoinette, The Journey, Coppola's film is based, is convinced the two did enjoy a physical relationship. Her assumption is based on Fersen's famous diary entry "reste-là", which he reserved for moments he had spent with lovers. But other scholars remain sceptical.

As Dr Burrows argues, there was "fertile ground for speculation" about Marie Antoinette's sexual dalliances, which Coppola finds so irresistible. She was pushed as a young girl into a loveless marriage with Louis XVI, which they were unable to consummate for seven years until he had an operation. There were many reasons why those who eventually found the pamphlets were prepared to believe them. "Antoine" had, by then, spent money lavishly while France faced bankruptcy and she was suspected of plotting to crush the revolution.