WHEN most millionaires appear in court their wives are either a) seeking a divorce or b) standing supportively behind them as they are attacked by former colleagues.

Barbara Amiel, currently in a Chicago courtroom where her husband, Lord Black of Crossharbour, is accused of racketeering, is doing neither. Far from divorcing, the couple seem more united than ever. Far from standing stoically behind her husband, Barbara Amiel seems to constitute part of the case for the prosecution.

The Blacks' fall from grace has been so spectacular that it is being followed across continents. Last week, the former editor of the London Times, William Rees Mogg, wrote that Conrad Black is like Gatsby. On Thursday, Conrad Black replied: "I understand he meant well, butf Gatsby was an amiable charlatan who ended up being murdered in his own swimming pool."

One thing is for sure, Barbara Amiel does not resemble the shy and outwardly gentle Daisy, Gatsby's beloved.

Amiel is a fiery figure who once famously said "my extravagance knows no bounds". This was bad news for workers at her husband's newspapers, who were denied pay rises as she hit the shops.

In 2002, even Vogue magazine was amazed to visit her home and see "a fur closet, a sweater closet, a closet for shirts and t-shirts and a closet so crammed with evening gowns that the overflow has to be kept in yet more closets downstairs". Barbara Amiel remembers a teenage boyfriend's mother laughing at a scruffy outfit she was wearing in the days when she supported herself through secondary school.

"I sort of never forgot it, " she said.

Her mogul husband is thought to be a little frightened of her. Black's phenomenal spending, which lies at the heart of the case against him, escalated when the pair married in 1992: three homes, two private jets, and a birthday party for Barbara at La Grenouille restaurant in Manhattan which cost $42,870. This lifestyle, and her love of the high life, prompted the London Times to entitle a profile of her 'Black Narcissus'.

The inventory of handbags, opera tickets and exercise equipment he bought for her has been listed not just in court but in the newspapers. Last week, in a moment of weakness or perhaps of clarity, Amiel described journalists as "vermin".

Until pretty recently, she was a journalist herself. This did not prevent her from calling a female producer for a Canadian television station "a slut" when the woman tried to follow the couple into a lift. "Journalists are vermin, " said Amiel. "I used to be a journalist and I never behaved like this. I did not doorstep and I did not hold my nose in the elevator."

It appears that in Chicago, where the case against Black opened last week, feelings are running very high. But then, feelings always appear to run high whenever Amiel is around. Her green-eyed beauty is said to reduce powerful men to jelly.

Now 66, her couture dressing, iron discipline and devotion to plastic surgery have kept her beautiful. Certainly her husband, four years younger, seems as loyal to her as ever, and still in her thrall. Photographs show him looking at her adoringly as she strides to court, always slightly ahead of him. His daughter Alana, 24, from his previous marriage, is the only member of the party who manages to smile.

Conrad Black, once proprietor of the British Daily Telegraph, is Canadian by birth. He is now accused of looting $84m from his own Hollinger media empire. He is charged with money laundering, obstruction of justice and fraud. The racketeering charge has been levelled under the US's Racketeer Influenced and Corrupt Organisations Act (1970), more usually used against organised crime and street gangs. If found guilty, Black faces fines of $164m and more than 100 years in jail.

One of his defence lawyers is Edward Genson, who is something of a celebrity in Chicago. Genson suffers from a neuromuscular disorder which means that he has difficulty walking. He is currently suffering from a client who is so arrogant that he doesn't even stand up when the jury enters the courtroom. Genson has had to make light of this. "By the end of this, we're going to teach him not to lean back in his chair, " the lawyer said of his celebrity client. He told the jury that, apart from "a bad attitude you're not going to find a single thing that's wrong". In court, Conrad Black is seen chatting to another Canadian journalist, Mark Steyn, who is covering the case.

In fact, Genson has spent some energy trying to humanise Conrad Black. He refers to his client as Conrad and professes amusement at his bombastic style in writing emails. Genson told the mainly female jury that Conrad Black and his wife led a life "different from ours. Not better, just different."

This is undeniable. Not for Conrad Black the quiet pleasures of heli-golf and the odd racehorse. He has published a very well-received biography of Franklin D Roosevelt. He attended his own fancy dress party as Richelieu, the corrupt French cardinal (Amiel went as Marie Antoinette). Famously, he once wrote in one of his own newspapers a heartfelt defence of the mini skirt. (Barbara Amiel has very good legs. ) But while her husband was born to wealth, Barbara Amiel had to scramble for it. When she was eight, her father left the family for another woman. He later committed suicide. It is said she left home at 14 to live . . . though not to work . . . in a building that was a part-time brothel. In 1983, she became the first female editor of the Toronto Star. Her second husband was the anti-Communist Hungarian George Jonas. A book on a murder, By Persons Unknown, won her the Mystery Writers of America Non-Fiction Award in 1978.

On her third marriage she moved to Britain. Her right-wing views and robust support for Israel meant she fitted right in with Rupert Murdoch's Sunday Times, where she became a columnist. She had always been a spender, but when she married Black in 1992, she hit the big time. As one Canadian journalist remarked, "Only a few hundred women in the world can afford to dress like Mrs Black, and Mrs Black may not be one of them".

Nevertheless, the Blacks had powerful friends, and in the early days of their marriage, high society in Britain and the US was happy to enjoy their lavish hospitality. Her 60th birthday party in New York was attended by Donald Trump, Michael Bloomberg and TV news anchor Peter Jennings. Her husband then wrote it off as a business expense.

They are both interesting, sociable and clever. Observers say they share a need for display and public approval. The strain of their disgrace has told on both of them.

Although they are staying in the Chicago apartment complex where Oprah Winfrey lives, they have not been socialising in the city. Instead, they have been spotted having a cup of coffee in Starbucks, while Barbara Amiel wore, of all things, denim jeans. In their native Canada, there has already been a television biopic of them, and presumably there will soon be a dramatic sequel.

C.V.

Born: 4 December 1940 in Watford, England
Family: Father Harold, a solicitor, left the family. Mother remarried and emigrated to Canada. One sister, two half-brothers
Education: Private school in England. Then supported herself through university in Toronto
Career: First female editor of the Toronto Star, 1983-1985
Married: July 1992, Conrad Black; her fourth marriage, his second
In the news because: Her husband is accused of spending his company's money on an extravagant lifestyle