Matthew Norman: The zenith of our celebrity culture

Even BBC Radio 4, global flagship of high-minded reporting, could summon the strength to lead bulletins with the trial only once Campbell made her way to The Hague

"So, this Mlle Carole White, mon ami, what did you make of 'er testimony?Was zere not one thing in her statement that seemed to you a leetle, shall we say, peculiar?" "Can't say that there was, Poirot. I mustn't have been listening at the time."

"Ah, Hastings, here is la difference between us. You leesten to everyzing, and yet you do not hear. But Poirot, he hears everyzing, n'est-ce pas? And what I heard was Miss White's suggestion that La Belle Campbell and Monsieur Charles Taylor's men were, 'ow you say it, text messaging one another regarding ze delivery of ze stone..."

How we have reached this pass is one for tomorrow's cultural historians to unravel, and the best of luck to them with that. But, somehow, the war crimes trial of a suspected genocidal tyrant has been transformed, by the catalyst of celebrity, into Agatha Christie's The Mystery of the Blood Diamond. This tale is so suffused with Agatha touches (jewels, women bitch-slapping each other to bits, even its very own Blue Train) that the slaughter of untold numbers of West Africans and the butchering of their babies struggle to make the cut as side issues. Even BBC Radio 4, global flagship of high-minded reporting, could summon the strength to lead bulletins with the trial only once Naomi Campbell had made her peevish and petulant way, like a spoilt Eurotrash teenager dragged to church on Good Friday, to The Hague.

The carnage allegedly perpetrated on his own people and those of Sierra Leone by Charles Taylor... well, it's desperately sad and all that (Africa, eh? What can you do?), and he does seem a jolly bad egg. But that staff-assaulting harridan Naomi Campbell, she's the 24-carat monster of the piece, what with her reluctance to testify and her proud ignorance of a dictator whose long-running trial the rest of us had seen fit to ignore until she descended, like a Prada-clad dea ex machina, to give it life.

Having said that, the allegations about Mr Taylor's conscription of boy soldiers and his deployment of rape and enslavement to stoke Sierra Leone's civil war and enable him to get his hands on the diamond mines make a gratifyingly lurid undercard to the main event. Yet the real story is that of the supermodel, her embittered former agent, the earth-mother Hollywood actress, those "dirty-looking stones", and the night in September 1997 when all the above coalesced in Pretoria, like Christie characters congregating for a murder, for dinner chez Nelson Mandela. This is where the fascination lies.

Was Miss White driven by hatred of her erstwhile employer, whom she is suing for compensation, to spray false accusations at the legendarily ill-tempered catwalk diva?

Did Mia Farrow, who one trusts took the chance to pick up a couple of Surinamese immigrant children on her Netherlands jaunt, hear Ms Campbell say over breakfast the following morning that Mr Taylor had given her the gem? Or is Woody's ex that classic Agatha archetype, the ageing actress motivated by envy of a younger woman's beauty? And cher Hastings, for zees is what I heard to excite the leetle grey cells but you did not, was it possible to send text messages at all in the South Africa of 13 years ago?

Now there may be those, loftily observing the frenzied interest in Ms Campbell's appearances and the conundra they throw up, who muse on warped priorities and the commentary they offer onourdecadent selves. Until now, cliché held that the age of celebrity reached its apogee a few weeks before that dinner in Pretoria, when the collectivehysteria provoked by Princess Diana's death hadthreatened the monarchy. Four Septembers later, when 9/11 apparently changed the world, it was declared that along with those in the twin towers and aboard the various airliners, al-Qa'ida had killed the obsession with famous people stone dead.

Here we are another nine years on, and whether or not it's altitude sickness at such a height clouding the mind, it's impossible to imagine how the imperium of celebrity could rise above this latest zenith. From Naomi Campbell's dominance of a trial concerned with crimes against humanity, the only way, as Yazz came so tantalisingly close to identifying, is down. Or so you might wish to believe.

Looking down the years from this vertiginous height, the war crimes trial you feel sorry for is Nuremberg. No doubt it thought it made quite a splash, what with the convictions of 19 of the 22 Nazi defendants. With the benefit of freshly minted hindsight, however, its flaws become painfully apparent.

Marlene Dietrich may have appeared in that timelessly magnificent 1961 film Judgment At Nuremberg, but neither she nor any major female celeb gave evidence at the trial itself. Not Leni Riefenstahl, not the Andrews Sisters, not even, God help us, the Mitford sisters.

How Hartley Shawcross forgot to call Oswald Mosley's missus is beyond me, but the oversight cruelly denied Alvar Lidell the chance to intone: "This is the home service of the BBC, and here is the news. In Nuremberg today, Diana Mitford told the court that she assumed the large diamond Herr Hitler gave her, during a visit to the Bertesgarten in 1936, was zirconium. She further insisted that the pearl earrings she received from Hermann Göring during that same visit 'looked like the most frightful tat that might have fallen out of a Christmas cracker, so I gave them to Frau Boormann'.

"Mrs Mitford's evidence was later contradicted by Betty Grable. Having remonstrated with the court for delaying the completion of her new musical motion picture, Mother Wore Tights, Miss Grable claimed that she overheard Mrs Mitford telling Eva Braun that the earrings were 'perfectly exquisite', and that she planned to wear them to His Majesty the King's dinner dance, Adolf's Other Ball, to be held in the Royal Albert Hall shortly after her return from Germany. In other news..."

What did they know about how to stage a decent war crimes trial back then? We shouldn't be too harsh on Shawcross and his colleagues if they naïvely assumed public attention could be held by nothing more captivating than the intimate details of industrialised genocide. Who knows, in the banal world of 1945 perhaps it was. In these enlightened times, no horror that unfolds beyond our borders - avoidable malarial deaths in the developing world, the trafficking of human beings, or malevolent acts of God - has profound meaning and the power to affect until sprinkled with the magic dust of fame.

Naomi Campbell's reluctant demotion of Charles Taylor to the bit-part bad guy at his own war crimes trial may mark an historic apex, but the syndrome has been with us for the quarter century since Band Aid at the very least. So the real mystery of the blood diamond isn't what La Campbell knew or when she knew it, cher Hastings, or even what Mama Mia claims she said about the gemstone over the croissants.

It is that we somehow retain the capacity to be staggered when a Radio 4 news bulletin, of the sort that had studiously relegated this trial down the running order for the better part of three years, begins with the words: "The supermodel Naomi Campbell..."