In grand opera, characters fall passionately in love with the wrong people, but at least they don't have second thoughts. No "friend" appears on stage after Violetta's tragic death to murmur that she always had her doubts about Alfredo, while Butterfly remains true to Pinkerton (unwisely, in my view) to the very end.

Yet only 10 days after his death, friends – perhaps that should be "friends" – of the great Italian tenor Luciano Pavarotti are spreading poisonous stories about his second marriage, claiming that it was a terrible mistake and he was driven to the verge of suicide by his second wife Nicoletta Mantovani.

According to stories circulating in the Italian press, Pavarotti spent his final days a tormented, lonely man, cut off from his friends and regretting that he ever left his first wife, Adua Veroni, with whom he had three daughters. In some versions, Pavarotti is even said to have authorised friends to make these lurid allegations after his death, a detail which, if true, is certainly not to his credit.

The rumours have been denied with equal vehemence, notably by his grown-up daughter Cristina, who dismissed them as "hateful gossip". A dramatic near-deathbed "confession" last month to the wife of one of his friends – "I am in a bad way... I am isolated. My friends do not visit me any more" – appears to be self-contradictory.

Other friends and associates have come to the defence of his second wife, saying that her only quarrel with Pavarotti was over his reluctance to exercise or reduce his food intake. This is the one element in the sordid tale that has the ring of absolute truth, for the simple reason that she, aged 37 and the mother of a young child, had every reason to fret about the state of her husband's health.

Pavarotti's heavenly voice was certainly not the product of a heavenly body, and any woman whose husband is both 34 years her senior and morbidly obese could be forgiven for trying to change his habits. In the most extreme version of the story, the tenor was so unhappy with his wife that he was considering changing his will, suggesting that what really interests at least some of the rumour-mongers is the fate of the fortune (estimated at £250m) he accumulated in the process of singing about death-defying passions.

At one level, what is being said and written about Pavarotti now may be an unusually swift corrective to the excessively adoring tributes that followed his death. Despite the presence at his funeral of ubiquitous rock star Bono and dignitaries such as the Italian Prime Minister, and the live TV coverage of the event, it was perfectly obvious to any detached observer that Pavarotti's judgement was seriously flawed; his excessive weight, his notorious unreliability and his much younger wife spoke volumes about a long-standing practice of generous self-indulgence.

This would not matter, except to his family and closest associates, if such habits were not misread by people used to treating celebrities with some of the reverence that used to be reserved for royalty. In death, Pavarotti was eulogised as if he were a world leader or great philanthropist rather than an accomplished singer whose appearance could not have been further removed from most people's idea of a romantic hero.

Less than two weeks later, it appears either that Pavarotti was disloyal and self-pitying, or he chose his friends very badly. This is dreadful for his widow and his ex-wife, who are being forced into a rivalry they may not feel, and is doing incalculable damage to his public image. The latest events are more Jerry Springer than La Clemenza di Tito.