About twenty years ago I was at a house party deep in the English countryside when a couple joined us for dinner on the last night.

He was of impeccable lineage and titled, although rather lacking in charm, I discovered. His wife, who sat opposite me, was quite simply mesmerising.

Although in her 60s at least, her obvious beauty had softened to a fine-boned loveliness enhanced by the smile that played constantly on her mouth.

It was plain that her conversation was enchanting the men on either side of her and I caught allusions to the opera, the ballet, New York's Carlyle Hotel, the Georges V, and other pastimes and places favoured by the rich and privileged.

Later, talking to her on my own, she used the same art of making me feel terribly interesting and amusing that she had obviously used on her dining companions.

There was the trace of a foreign accent I couldn't place, but her vowel sounds were pure upper class English.

After she'd gone, like a star struck fan, I wittered on about her to my hostess.

She seemed amused. "Well, she did have the finest training in every possible department," she said, laughing. I was puzzled and asked what she meant.

"She was one of Madame Claude's girls. You'd be amazed how many are well-respected figures in society. But the men always know. Well, they would, wouldn't they? They probably knew them intimately."

And so I heard of Madame Claude for the first time - the number in the then little black books of the world's most powerful men.

She was quite simply France's most famous brothel keeper, founder of a high-class escort agency involving hundreds of girls in Paris in the 1960s and 70s.

Among those said to have enjoyed their favours were John F Kennedy who asked for a prostitute who looked like his wife Jackie but "was hot."

Marlon Brando, Rex Harrison, Moshe Dyan, Gadaffi, Marc Chagall, Aristotle Onassis, the Shah of Iran were just a few of the wealthy, titled and famous who called upon her discreet services.

The call girls were known as her 'swans' and were mainly tall, stunning failed models or actresses, many of them from the House of Christian Dior couture. She preferred foreign girls, usually Scandinavian.

They were taught etiquette, how to avoid the eating faux pas when enjoying the food of their escorts; for example fingers only for asparagus, fork only for fish and seafood, no additions to a simple spoon of caviar etc.

And they were taught the secrets of classic dressing, amusing conversation; the importance of total discretion and of course, every which way to please a man sexually.

Their price was high and quite a few ended up as the wives of the men who found them far too valuable to let go. Some names were given to me that night that astounded me but I was sworn to secrecy.

Well, if they were all as elegant and delightful as the 'swan' I'd met that night, I could see why.

Somehow it seemed so very French and fitting that they should have come from the stable of a Chanel-clad Madame. It elevated an age-old trade - always legal in France - into a profession with qualifications as demanding as any.

The swans and Madame Claude came to mind this week as the tawdry, lurid evidence in the case of Dominique Strauss-Kahn and others poured out from a court in Lille.

The disgraced former boss of the IMF and a once-contender for the country's presidency, was charged with aggravated pimping - of organising and paying prostitutes to attend orgies.

He claims he did know that 'the equipment,' as he dismissively called the girls, were prostitutes. Women, he said arrogantly, came onto him all the time because he was a powerful man. And anyway a naked woman was just that. Who could tell if she was a whore or just an ordinary woman.

Admitting he liked his sex rough, he called himself a libertine who indulged with other libertines in group sex. The details that emerged were sordid in the extreme.

The case may or may not be over when you read this. He may or may not be found guilty.

It doesn't matter. The trial involving call girls far from Claude's swans of old has stripped away any still lingering belief that the establishment, with their mistresses and their 'libertine' louche ways, should be seen as a sophisticated advert for French sexual tolerance.

It is plain from the reporting and the distaste of the usual apologists for the elite, that certain practices and misuse of power are unacceptable in any language.

To the abused prostitute, the betrayed wife, the 'always the mistress,' there is ultimately nothing frightfully sophisticated about this so-called French way of loving.

And anyway, as the song says: What's love got to do with it?

I have no idea what tricks the swan I met had to turn in her time with Madame Claude. I'm told Claude vetted the men as thoroughly as the girls.

I do know, instinctively, whatever the reward, she would not have entertained DSK.

She had too much class for that.