PRICK UP Your Ears is a salacious bio-pic which explodes the short, brutal and sexual incandescent career of playwright Joe Orton across the screen. It's also a hugely acidic black comedy of the submerged Gay Sixties subculture.

Orton - played by Gary Oldman, is eventually murdered by his more staid live-in lover Ken Halliwell (Alfred Molina), but the film is brilliantly funny, provocatively vulgar, and ravenously hungry for experience. A life that burns meteorically from encounters with Paul McCartney to anonymous blow-jobs in the Holloway Road gents, from scripting mischievous movies like Loot and Entertaining Mr Sloane, to lustful group sex with Arab boys in Tangiers. The movie leaves nothing to the imagination - except for the real-life presence of Kenneth Williams.

Extreme discretion edits the Carry On star clear out of the story. But he was there. He was the neurotic Inspector Truscott in a role especially written for him by Orton in the original stage production of Loot. Uneasy with the character, he played it "like Himmler." In John Lahr's definitive biography on which Prick Up Your Ears is based, a smugly preening Kenneth Williams is photographed between the thuggishly rough-trade Orton and Halliwell in Tangier in 1965.

And in Williams' newly published diaries he leaks more details. "Went up to see Joe Orton and Kenneth. Both were so kind. We talked a lot about homosexuality . . . John walked me all the way to Kings Cross . . .". But unlike Orton who delighted in sleaze and its capacity to shock, Kenneth Williams was never at ease with his sexuality. And Orton playfully found such reticence an irresistible target. One of the last people to see the duo alive, Williams humourlessly confides to his diary his continuing indignation at Orton's transparently teasing accusation that Williams 'posted' used condoms into pillar boxes.

In life, Kenneth Williams claimed to be celibate, and the di-aries more or less confirm this. His movie image may have been Carry On Camping, but he confined his sexual activity to the long wank sessions his entries detail. He records the duration of some wrist-jobs in exact minutes and seconds, fuelling them on mildly masochistic fantasy. "Masturbatory success is the result of imaginative conceit," he pronounces vainly.

"Williams was surprising to meet" says Lahr, "a complicated, touching man who bore no apparent relation to the haughty buffoon of the Carry On films or the whining camp voice from Round The Horne or Beyond Our Ken. His actual speech was clipped, animated and vivid; but in recounting his stories his voice slipped easily into the wide range of delicious postures that had made him one of England's most popular comedians, sprouting plummy and pinched vowels as it swooped from posh to dead common. Williams made the act of speaking funny."

Those complications go way beyond the 'tears of a clown'. Kenneth Williams veered between narcissism and self-disgust and prurience and prudery, his comedy always tinged with neurotic hysteria, his sexual itch attracted to, and repelled by, the homosexual life-styles his most outrageous routines lampooned. "Curious how far away I feel from all this sex twaddle," he writes (26th Feb 1962). "People wanting to possess people. Ridiculous."

He achieved stardom through radio, yet never considered it a 'serious' medium. He'll be best remembered for the affected anguish of his performance in the Carry On films - shocked by the avalanche of Hattie Jaques advances, outraged by Sid James' earthy innuendoes - trash movies that are now the subject of reappraisals as the quintessence of bawdy English smut. Yet he despised them too. His primping limp-wristed style is best captured in Carry On Dick, or Carry On At Your Convenience in which he plays Mr. W.C. Boggs, a lavatory manufacturer on a Works Outing to Brighton. On the pier he debates the validity of 'Gipsy Rose Lee'-type clairvoyance with Sid James . . .

"Fortune Tellers? They're all fakes, looking in their crystal . . . er . . .".

"Balls?" suggests Sid helpfully.

"I quite agree" flounces Williams with a haughty snort.

His diary entry (for 20th Feb 1964) records: "The script of Carry On Spying is so bad that I'm really beginning to wonder. I've changed one or two things but the witless vacuity of it all remains."

When radio star Kenneth Horne died, a Kenneth Williams tribute 'soundbite' caught his bitchiness in full flood. Horne, he said, was the "rock" around which all the comic insanity revolved - a double-edged scratch-your-eyes-out which infers more at second glance.

Kenneth Horne was an established figure in BBC radio comedy with appearances dating back to Much-Binding In The Marsh during the war years. His was the star name that provided Williams with his point-of-entry to a mass audience. Beyond Our Ken ran from 1958 to 1964, written by a fledgling Barry Took and Eric Merriman. It was immensely successful, remaining a big-selling item today through a series of BBC cassette editions.

Horne's rich indulgent tones provide the framework for absurd sketches, Panel Shows and songs spoofing styles and genres through the surrealism provided by the visual third eye of the listener's imagination. It was followed by Round The Horne (1965 to 1969) with Took now in partnership with Marty Feldman. Together they scripted 50 out of the 66 episodes.

Kenneth Williams had appeared in the Hancock's Half-Hour TV show, but fell out with Tony Hancock and was subsequently dealt smaller and smaller bit-parts until he was effectively written out. Instead it was Horne's radio shows that enabled him to develop his persona through the grotesque vocal exaggerations Lahr describes. He became Ramblin' Sid Rumpo the Protest Folk singer with ersatz dialect verging on the edge of blue in opuses like 'The Ballad of the Woggler's Moulie'. "Keep it clean" urged producer Jacques Brown, "precious rather than poofy." He was also the wheezing old pervert J Peasemold Gruntfuttock in sketches including one about phone bugging. He shrills: "Hold on, there's someone on my extension!", then "my private discourses are being interfered with!"

"It's hard to tell whether you're boasting or complaining" comments Horne, and "we'd never get away with this on television" in a knowing aside.

But Williams' richest subterfuge came in league with Hugh Paddick as the mincing 'Julian and Sandy', lifting the secret gay code of 'polare' and inflicting it into a million Sunday lunch-time nuclear families. Developed by the homosexual subculture as an internal language to baffle outsiders, Kenneth Williams' game drew it through the airwaves in delicious satires of 'omi palone'.

An omi is a man, palone a woman. Taken together the phrase denotes a gay man. To vada his lallies is to look at his legs, his face is eek, so a good-looking boy is bona eek, with nice riah (hair). The words might have French or Italian derivations and polare can be traced back to the 18th Century with some even claiming to find it in Shakespeare.

Williams and Paddick requisitioned it as their private in-joke, both party to its double-meanings, and ridiculing the community it sprang from.

As a kid I loved the characters. I imitated their vocabulary in the school playground without making the gay connection. To me, Julian and Sandy weren't sexual deviants. They were just brilliantly funny. They still are. One week Mr Horne visits them, this time in their Advertising Agency bijou studio-ette. "I used to specialise in cigarette adverts. I was never alone in the Strand", primps 'Julian' Williams. "Whatever the pleasure - I completed it. I used to sit on this horse in a polo-neck, all butch and dominating. Then I'd take a puff, and gallop off . . .".

The punchline is that his advertising career was brought to a halt by anti-cigarette legislation when 'They banned fags from TV!'. The delivery lusciously exploits every possible nuance of double entendre to the maximum, the two voices building and developing the camply saucy characters into beautifully realised absurdity.

Mary Whitehouse and Conservative MP Cyril Black weren't so amused. But BBC Director General Hugh Green defended and supported the programme, because he liked 'dirty shows'.

Kenneth Horne provided Williams with the opportunity to become a national star. Yet rather than acknowledge that debt he used the posthumous tribute 'soundbite' to demonstrate how his own talent reduced Horne to the role of straight-man. An act of hideous disloyalty, even if there's a trace of truth in what he says. Kenneth Williams could be an unpleasant man. Unlikeable, even to himself.

He was born on 22nd February 1926, maintaining a close 'open' intimacy with 'Louis', his mother, throughout his adult life. He began writing details of his thoughts and experiences at fifteen, in a Collins Emerald Diary, recording everything clear down to his collar and hat size (14 and 7 respectively).

Edited into manageable, but still hefty book form by Russell Davies and published by Harper Collins (£20.00) the diaries are often unsavoury, irascible, candid and scurrilous, but seldom boring, with Williams dishing the dirt in uncensored musings on his relationships with Hancock, Orton, Stanley Baxter, Barbara Windsor, and more.

To Observer journalist Peter Conrad, the comedian regarded his sexuality "as a jest of nature for which he could not forgive himself." Also, for most of his life, with homosexuality illegal, it was an inclination that made him technically a criminal. Unlike Joe Orton he was never able to 'come out'. It was a reticence that forced him to repress, distort and characterise himself through the merciless comedy flagellation of Julian and Sandy and beyond. Yet he never engaged in 'penetrative intercourse', fearing and loathing the spectre of his desire to do so, and quick to detect traces of his own effeminacy.

"I heard me on the radio doing Desert Island Discs" he writes (22nd May 1961). "Not bad really. Voice came over a bit common and poofy." And later, with a near-tragic irony, "I am now looking like the elderly preserved queen I used to meet pityingly at parties."

Nothing seemed to give him real pleasure. He visits Dublin to guest on the Late Late Show, staying at Bloom's Hotel, and " . . . only in Ireland could you have found such an incongruous and unfunny mixture." He could have been writing about himself.

The Carrying On came to a halt on the 14th April 1988 with a barbiturate OD. It sometimes seems that Kenneth Williams was a character from a Joe Orton black comedy, ripped apart through psychological and sexual warfare for our amusement.

And we were amused.