When I first heard about this book, the publicity spin on it suggested that it was going to be little more than a tiresome rip-off; ooh, the chimpanzee who starred in the Tarzan movies has - ho ho! - written a book! I didn't even bother filing this away under "books that should not be".

And then I was sent the hardback, and urged by a colleague to read it. And since then, I have been urging it on anyone who has cared to listen, for it is by some margin the most audacious, funny and even moving novel that I have come across in years.

The conceit is, it is true, that Cheeta the Chimp has written his Hollywood memoirs. But, after a throat-clearing "Note to the Reader" that is much funnier once you have read the book than before, you soon realise that the extraordinary nature of this autobiography extends beyond the premise that it was written by a chimpanzee. We begin in the grounds of a country house in England, where Rex Harrison, his wife Rachel Roberts and Dickie Attenborough are taking a break from filming "Fox's disastrous megaflop Doctor Dolittle", and taking bets on whether Cheeta will be able to get down from a monkey-puzzle tree. "Why don't we forget the money?" asks Rex of his wife. "If the monkey makes it you can sleep with Burton, if he'll have you, and if it doesn't, then I can divorce you but you have to promise not to kill yourself." A couple of pages further on, and Cheeta is describing Harrison as "universally despised, impotent, alcoholic, cruel, vain, brittle, snobbish and mephitic but still, under that carapace of protective acerbity, [a] very gentle and insecure human being".

This, then, is an alternative take on Hollywood's golden age; the place where, as Cheeta describes it, the actors perform dreams which are soaked up by the public watching them being played out on the screen. And the price of this is that the "dreamers", as Cheeta sometimes calls the stars, lose their minds. Cheeta works the grimmest parts of the fairytale even into his similes: "But that was as foolish a dream as Lana Turner's daughter Cheryl's hope that her stepfather Lex Barker would stop raping her." There is plenty more near or even past the knuckle like that, and James Lever knows how funny this can be when he writes "Chapter 8 has been removed on legal advice", yet allows us some clue, in the index, of what the chapter might have consisted of: look under "Williams, Esther" - "nauseatingly self-justifying autobiography of, 225", and so on.

But this is far more than a wicked spoof tell-all. It operates, and works smoothly and well, on several levels: it is a Swiftian satire, as Cheeta walks through the world observing human foibles and, often as not, getting them exactly wrong, as when he imagines that the stuffed animal heads adorning the walls of one actor's house are all old pets, lovingly preserved. It is a textbook example of the unreliable narrator ("Incidentally, during this conversation, Marlene [Dietrich] and Mercedes [de Acosta] were stimulating each other's sexual organs. You can well imagine how bored I was watching them ..."). It is also deeply funny. The story of what happens when Johnny Weissmuller and David Niven borrow Douglas Fairbanks's Rolls-Royce, and rig it up so it looks as if Cheeta and Jackie the MGM lion are driving it, will have you laughing out loud for 10 pages.

But it is also a love letter to Weissmuller, the original star of the Tarzan films; a tribute that bursts its own narrative confines, and stands the novel on its head, to become a hymn to a certain kind of beauty and innocence. Weissmuller is as much the star of the book as Cheeta.

And the prose ... well, no wonder people were wondering whether Will Self or Martin Amis were behind the pseudonym (only revealed some time after publication. There are signs, incidentally, that Lever has read, and tried not to overlap with, Self's splendid Great Apes). The prose is impeccable - supple, intelligent, penetrating, vigorous. A delight to read. Lever couldn't have got away with this without it.

Tarzan and His Mate, filmed in 1934, is exhibition-quality Art Moderne. It was shot day to day by uncredited co-directors, but its nominated director was the MGM production designer Cedric Gibbons, and it is visibly his creation, as were those showpieces of the era's high shine, The Thin Man, A Night at the Opera and The Philadelphia Story. The dreamiest of Gibbons's worlds, though, was the jungle put together from Californian locations at Thousand Oaks, the San Fernando Valley, and Lot Two at Culver City Studios, and stocked with an Eden of African animals (the elephants were Indian with strap-on flappy ears, but nobody's perfect).

Tarzan and His Mate is like an inlay of rare woods and chrome aboard a deluxe liner of the period, with its rhinos, lions, zebras and three prime primates prancing across the frieze. OK, Maureen O'Sullivan as Jane is Miss Grimacing Prim until she puts on a backless evening gown that looks to be of molten platinum, then loses it and bathes nude, whereupon she's delicious, notwithstanding that her underwater body was doubled by a pro swimmer.

As for the two alpha males, they are eroticism carnally incarnate. Johnny Weissmuller, Olympic aqua champion, is Tarzan, of beautiful physique and presence, his face magical and tragic as long as he maintains silence or restricts vocals to his unique yell. And then there's Cheeta the chimpanzee. When Cheeta, tending the wounded ape-man, brushes Tarzan's brow with leaves, you feel you shouldn't be watching such an intimate gesture.

There has long been a movie rumour, which goes unmentioned in this sensational-in-the-best-sense autobiography, that the chimp in Tarzan and His Mate isn't the 76-year-old Cheeta now in retirement in Palm Springs, the oldest living non-human primate in the world and the personality behind this curse and tell book. The whisper is that Weissmuller clasped to his bare bosom AN Other chimp, and that the celebrious Cheeta, aka Jiggs, who went on to star in 12 Tarzan movies, was barely past babyhood in 1934, not long off the boat from Liberia. All he did in the pic was a cameo as a cute kid. Before I read the autobiography, I might have credited the anon ape, fate unknown, but Cheeta's version is so much more believable. In his entranced recall, he was orphaned by the ordinary savagery of the real jungle, then saved by Henry Trefflich, supplier of monkeys to showbiz and medical labs; before the freighter docked on a New York pier Cheets/Jiggs had already dodged death by a perfectly timed skid on a banana-skin that knocked a black mamba off its murderous intent.

Cheeta first encountered cinema when on the run (more on the climb) in Manhattan, and what else should he see but King Kong? He immediately understood the Jungian truth of movies: that they are collective dreams "dreamed on to the wall" by their watchers. By the time he made it to Hollywood, evading lethal selection for the lab, and blows as he learned discipline, he was even more attuned to the art form: the actors enacted the dream "and as a kind of byproduct of converting the dream into the past, the cameras gave us our souls - they poured soul over us and if they gave you enough of it, you started to become an Immortal ... once the dream was in the past ... moviegoers would rush in their millions to live in it rather than in the present." Cine-poetry. James Agee would be jealous.

Of course, Cheeta's career wasn't all the philosophy of an art and multiple takes with Johnny through the length of a blissful afternoon. As Cheeta cheerfully volunteers, even during the golden years he spent 65% of his time masturbating in a cage, and, encouraged by breeders and Charlie Chaplin's entourage, fruitfully inseminating female apes. Off-set he met Johnny only a few times a year, when they and the usual suspects - David Niven, Douglas Fairbanks - got up to monkey business: practical jokes that ended in pranged automobiles; liquor, smokes and coke; weekly sex parties. (No he didn't. Especially not, as rumoured, with Dolores Del Río.)

Johnny also introduced his sequential wives to his true mate. Cheeta foresaw that number three, Mexican spitfire Lupe Vélez, would self-destruct; but just as he had done with the shrill O'Sullivan in Tarzan's New York Adventure, 1942, he had to exert himself to oust wife number four from the picture. Cheeta liked wife number five, but by then Johnny and Cheets were on the skids, with the Tarzan franchise sold to RKO and zombified dialogue displacing the powerful old vocabulary of umgawa and ahhheeyeeyeeyaahhheeyeeyeeyaaaah!

Cheeta's memory gets unreliable around Tarzan and the Mermaids, shot or not in Acapulco in 1948 - maybe it was the tequila-based coco locos he drank, or depression after being fired for temperament, or a valid artistic reaction to the degradation of RKO production values. He bypasses his appearance opposite Johnny's successor, that unclasped jackknife Lex Barker.

Cheeta registers everything else, though: the bummest of poverty row movies, Bela Lugosi Meets a Brooklyn Gorilla, 1952, the comeback that flopped in Doctor Dolittle, 1967, his decades on the back roads playing live dates until the mood of America changed and a tumble of touring chimps seemed less like a cheapo Marx Brothers act and more like exploitation. He aged better than many of his old acquaintance - Cheets never guested in a bad toupee as a suspect in a late episode of Colombo - and when he finally drifted into becalmed safety at the Creative Habitats and Enrichment for Endangered and Threatened Apes in Palm Springs, he had a past to express through a newfound talent for fingerpainting.

His subject is always Johnny. Not the bankrupt bodily wreck who fetched up in Mexico with a sixth wife and had a recording of the yell played thrice as his coffin was lowered into the ground; not the silver ghost that haunts the Turner Classic Movies channel; but the possibilities for immortality inherent in the collective dream - "It's hard to die when Mr Tarzan's around," to quote Barry Fitzgerald in Tarzan's Secret Treasure, 1941.

This book is great gossip - did Esther Williams feature in the section the lawyers pulled?; ace film criticism (yep, Robert De Niro sure does look like he's been on mouldy straw in the cage too long); and tremendous polemic - how well Cheets argues that an animated Pixar pixel hasn't suffered for its art, hasn't eluded death, there's no soul there even if every hair is exactly replicated. And it's the definitive buddy movie. These guys loved each other. As the trailer titles for Tarzan and His Mate say, "elemental passions ... never will it be surpassed".

Cheets, just one thing - your ghostwriter. You couldn't have tipped him/her a miniscule credit on the copyright page, down where they acknowledge that the paper sources were approved by the Forestry Stewardship Council? I suppose not, even though he/she is an inspired writer. Genius, even. But it's Hollywood. Print the legend. Aahhheeyeeyeeyaahhheeyeeyeeyaaaah!