Snapped in hard flash by every tabloid last week as she struggled to save her second marriage, it is clear that Madonna has ended up with the face she deserves: reconstructed and twitchy. But why has the woman Norman Mailer once called “our greatest living female artist” never had the insightful biography she deserves?

Her brother Christopher Ciccone's attempt may smack of revenge and petty innuendo, but at least it is written by someone who was there, who - by his own creepy admission - stood backstage with the Queen of Pop, sponging the sweat off her naked, rippling torso between numbers.

If this uneasy image has you reaching for the sick-bag, just wait. Ciccone's book is a vomitorium of cringy confessions. Madonna is labelled a myth-maker and a miser, who plies her brother with MDMA, has legs that look like “fat sausages” and is the sweatiest woman he's ever encountered. He denounces Guy Ritchie, her husband, as a homophobe (Ciccone is gay), and believes her adoption of David Banda, the Malawian toddler, like everything in her life, just served her image.

A good deal of this carping can be written off as a teenage tantrum. Ciccone (Madonna's younger brother by two years) seems to have spent his life in as an adolescent, yoked to this terrifying surrogate mother figure, first as her dresser, then as her tour director and interior designer. That said, nobody else has had this level of access to the Material Girl. The rest of her family saw little of Madonna once she vogued off to the airless stratosphere of superfame. But Ciccone was right by her side, washing the pointy bras.

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So what do we learn? For one thing, Madonna's image of herself as a benevolent babymama to her younger siblings is baloney. By Ciccone's account, she was as starry and remote as a child as she was to become later in life, and ruled the house like a tempestuous deity. Ciccone remembers that both he and his sister lost their virginity in the backs of cars to boys called Russell. “Trust her, though, to best me,” he sighs, “by having her first time in a Cadillac, not a Datsun.”

She was rude before fame, and ruder after it. As a struggling pop singer in New York, she encouraged Ciccone to leave his job and travel halfway across America to stay with her. When he arrived her first words were, “You can't stay here.” Then she fired him as her backing dancer when she hit the big time, insisting that he be her dresser instead. He found this demeaning, but reveals that Madonna is surprisingly prudish and doesn't like being naked in front of strangers.

Why did he put up with it? She would demolish him with screamed expletives or frosty silences, then come crawling for a compliment. “Most of us are far too dazzled by her fame and all the attention it brings us and quite simply don't want to rock the boat,” he explains.

Of course, it's the throwaway details of the fame years that really bring her oddness home: the open-top Mercedes she owned for 10 years without ever putting the roof down as it would damage her skin, the morning ritual of gargling salt water and pushing it out through her nose, the daily six-mile runs and the macrobiotic diet - a schedule that accounts for every minute of her day until she retires at precisely 11pm to face the crippling insomnia that ensures she sleeps for only three hours a night.

There is a distinct whiff of the automaton about her manners. When, in the mid-1980s, Playboy published nude pictures of her, taken before she was famous, she breezily instructed her publicist to call her father to let him know. When her first marriage, to the actor Sean Penn, fell apart, it was again the publicist who called Ciccone to say his sister would like him to come to Los Angeles to comfort her. Even in crises, Madonna keeps people at arm's length.

There are juicy cameos from Kate Moss, Johnny Depp, Gwyneth Paltrow, Naomi Campbell and Penn, to name a (very) few. Ciccone does cocaine with a lot of them. Both Courtney Love and Jack Nicholson swear to him it's their first time. Moss sidles up to Ciccone at a Versace show with the line, “Christopher, I need some coke and a glass of champagne.”

Ciccone weathers Madonna's rants, but money becomes a problem. He uses $65,000 of his own cash to buy some paintings she has requested, then she changes her mind after the purchase and refuses to reimburse him. Sotheby's doesn't do refunds and Ciccone spends months having to borrow money from friends while he arranges a resale. He suggests a contract for when he does up Madonna's next home, but when he sends it over, she calls him “a f***ing piece of shit”. He dispatches a return fax calling her “an ageing popstar”. She cuts him off, but he goes back begging a few weeks later. He needs the money.

It is Ritchie's arrival on the scene that heralds the death rattle of the relationship. Ritchie is boysy but insecure, Ciccone believes, and uncomfortable with his gayness. The evidence for his brother-in-law's homophobia is slim - in real terms, a few public-school-type nancy-boy jokes (none of which is directed at the author) - and Ciccone never considers the possibility that maybe Ritchie just doesn't like him.

Two years ago, with relations at an all-time low, Madonna became convinced Ciccone was a drug addict and offered to pay for him to go into rehab. The doctor promptly told him it was Madonna he was addicted to, and the therapy became the catalyst for Ciccone writing this book, which, reportedly, she is spitting mad about.

It pains me to say it (it's such a hackneyed read in many ways), but this is the best book ever written about Madonna. Never have her single-mindedness, her downright strangeness, been brought into such devastating hard focus. That her brother has to concede, after spending most of his life in her presence, that he barely knows her, tells you everything.

Not that the author deserves our sympathy. His prose smacks of an embarrassing man, skidding towards 50, whose entire existence is driven by a desire to cleave to a remorseless celebrity. “I've made you what you are,” rails Madonna in one of her toxic e-mails. “You wouldn't be anything without me.” Spot on, Madge. But now you both have to live with the consequences.

Life With My Sister Madonna by Christopher Ciccone with Wendy Leigh
Simon & Schuster £17.99 pp352

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