It was a suitably dramatic end for a man who had lived most of his life in the limelight. Gianni Versace had made celebrity an art form. His life was commercial-perfect; he had produced beautiful, glossy art books featuring his own houses and his own lifestyle. And on 15 July 1997 he was shot dead outside his South Beach, Miami mansion by a lone gunman. What followed was probably the biggest manhunt since Kennedy was shot. Within hours, Miami police were on the trail of a suspect, Andrew Cunanan, a young homosexual man already on the most wanted list for four other murders. But when they caught up with Cunanan in his hideout on a barge in Miami Beach nine days later, he too was dead, a single bullet hole in the temple.

The numbers of police assigned to the case could only be equalled by the army of journalists circling the corpse of fashion's brightest star. As tearful statements from friends and admirers poured out of fax machines in every newsroom, lurid speculation churned around newspaper circles about the circumstances of Gianni Versace's violent death.

In the weeks that followed, there was an undignified scramble to rush out books about his life. A feature film went quickly into production: The Versace Murder, starring Franco Nero as Gianni and directed by Menahem Golan, was rolling within two months of his death. The film-makers said simply: "It's important to be the first movie out. The curiosity factor has got to be immense."

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The first book to appear after the designer's death was written by Vanity Fair journalist Maureen Orth and titled Vulgar Favors: Andrew Cunanan, Gianni Versace and the Largest Failed manhunt in US History. The book, published by Delacorte Press in New York this year, was an account of Cunanan's life and the string of murders he committed before his own death.

Though the book was primarily an investigation of Cunanan's sordid and chaotic life, it was also alleged that a post mortem had indicated that Gianni Versace was HIV positive when he died.

Prior to his death, Gianni Versace had had surgery to remove what was described as a cancerous growth of the ear. He immediately began to put his affairs in order, dividing up his assets and bequeathing the business to his 11-year-old niece Allegra.

A spokesman for the family described the book as "scurrilous". And the critics weren't too impressed, either. The New York Times dismissed Maureen Orth's "febrile attempts to tattle and titillate", and described the book as "voyeuristic". But part of the author's study was the unhealthy curiosity of the press: "Vulgar Favors is framed as both a cautionary tale about unchecked materialism and hedonism and an expose of the seamiest underside of gay life, the possibly fatal bunglings of law enforcement and the voracious appetities of scandal-chasing journalists."

Gianni Versace, beautiful, exotic and fantastically wealthy, certainly attracted a degree of curiosity, which only increased with his death at the tragically early age of 50.

The first challenge facing his distraught sister, even before taking his place as chief designer, was to cope with the glare of publicity, from which she had previously been sheltered by her brother. "I'm not Gianni," she told an interviewer earlier this year. "We were very different, but they still complain, `oh, she does not do this and this like her brother'."

Perhaps more than any other design company, Versace is fiercely protective of its reputation. And perhaps more than any other designer, Donatella does not allow any slurs on the reputation of the company to go unchallenged. Defending themselves and their name is something to which the Versace family has devoted considerable resources, both before and since the violent death of Gianni Versace in July 1997. They have successfully sued several British publications for libel over inaccurate stories, including the Independent on Sunday and The Observer. An editor said: "They've got the fiercest lawyers in town. Everyone in Fleet Street is terrified of writing anything about them in case they get it wrong."

The latest to feel the firm's displeasure is British writer Christopher Mason. The book, titled Undressed: the life and times of Gianni Versace, was to be published by Little, Brown in July this year. Mason's book touched on Gianni's childhood, his relationships, and his brilliant manipulation of the media.

Last week, lawyers for the Versaces threatened legal action if Little, Brown went ahead with publication of the book, on the grounds that it was full of inaccuracies and misrepresentations.

A spokeswoman for Little, Brown said in a statement: "In mid-March, we received letters threatening legal action. We agreed with Christopher Mason that it could not be published in its present form, and he withdrew it."

Versace have explained that their concerns are solely about inaccuracy. Emanuela Schmeidler, Versace's Milan spokeswoman, told The New York Times: "It's not about a good biography or a bad biography. It's about a serious biography." Versace's New York spokesman said: "We did what anyone else would do under the circumstances, which is to defend ourselves and our name." The author has admitted that he struggled to find sources who would talk on the record about Gianni's private life.

And he is unlikely ever to find any. Generally, the fashion industry works in a symbiotic relationship with writers who are given extravagant gifts and invited to lavish parties, particularly during the couture shows, where guests include rock stars and film divas. In the weeks before the shows, fashion writers are more than usually eager not to displease the couture houses, lest they lose their coveted seat in front of the catwalk (the designers have the power in this scenario: how is a writer to review the show if she hasn't seen it?).

Magazines rely heavily on advertising by fashion houses, most of whom have branched out into luxury items such as handbags and perfumes, even hotels; publishers' commercial departments are understandably unwilling to jeopardise lucrative advertising deals with careless or negative editorial.

One source, who, in common with almost all fashion writers and publishers contacted in the course of researching this article would not be identified, said: "A major designer wields a great deal of power in fashion circles. Occasionally, big designers will block big-name editors from their shows, but a lot of the time it's a publicity stunt. But it's always newspaper editors, never magazine editors. Designers need the magazines as much as the magazine needs the designers."

Typically, Versace has always given bigger, better parties than anyone else. The Versace hospitality knows no bounds. "All Italian designers give gifts," says one fashion insider. "It's in the nature of their hospitality. The Versaces are gift-giving types. They have huge dinners - and it makes doing business a lot nicer."

Gianni's sister Donatella has always run a very slick PR operation. While he focused on design, she worked on building good relations with supermodels and film stars. She was the first designer to forge links with celebrities, lending them outfits for high-profile occasions such as film premieres. The tactic worked brilliantly. The name of Versace, quite apart from the flashy, show-stopping style of the clothes, became synonymous with showbusiness. When Liz Hurley appeared at Hugh Grant's side at the premier of Four Weddings and a Funeral, she wore a pink Versace dress barely held together with gold safety pins. That Dress, as it quickly became known, made That Girlfriend a star overnight.

While Donatella was always Gianni's sidekick - the cool kid sister, with a gift for spotting what was hip - she was also Gianni's muse. Her influence as a trendsetter in her own right should not be underestimated. She inspired the trashy form of glamour for which the label became renowned. She became friendly with royalty and rock stars, who later became an essential part of the Versace image. The clothes were a rebellion against conventional good taste and minimalism, and celebrities loved them. Since the late 1980s, their advertising campaigns have featured stars including Kate Moss, Naomi Campbell and Jon Bon Jovi. Madonna is Donatella's "favourite person in the world".

Although Donatella has no formal training, she worked alongside Gianni for 20 years. He welcomed her input, and took up suggestions such as adding bondage straps to a range of dresses. Donatella moved into designing accessories, and went on to head the Versus and Istante diffusion lines.

She was with a seamstress in Rome, preparing for a fashion show, when she was told that her brother had been killed. Despite later admitting that she was in an emotional "fog", she assumed his role as head of the empire with her older brother, Santo. She wasn't expected to succeed. There were questions as to whether she would have the skills and experience to run the business, and whether she had her brother's pre-eminent talent for design. "I didn't understand the pressure of my position until much later," Donatella said in a recent interview. Her first two collections met with a muted critical reaction, but the company has since flourished, and now her clothes are rarely off the front pages.

Certainly, Donatella Versace has come too far from the dreary provincial town where she grew up, to let the family empire be compromised by any idle smear job. And yet, the very press intrusion that the Versaces so resent came about, in part, because of the slick PR machine that Gianni Versace created. The more pictures Gianni produced of the perfect family in the surf, or surrounded by their lovely things and their lovely friends, the more they attracted envious attention. Gianni was an icon, classically good-looking, a lover of classical art. Donatella and her children are privileged, good-looking, and surrounded by privileged and good-looking friends.

More than anything, Gianni and Donatella Versace are victims of our times, of the insatiable desire for every last detail of the private lives of the rich and famous. But as long as Donatella remains at the helm of the empire her brother created, the only glimpses we will get will be what she allows us to see - on the catwalk, in the showrooms and on the pages of glossy magazines.

Additional reporting by Catherine Bassindale