When John Webster, an attorney, was sent to prison on a fraud conviction, he had no one to turn to. "I had no idea what prison was like," he explains. "My plan was that I'd return to being a lawyer after my release, but then I realized I could start a business helping others adjust to prison."

For fees as high as $12,500, Webster's firm, National Prison and Sentencing Consultants, performs services such as "pre-surrender incarceration services," also known as hand-holding for anxious soon-to-be-prisoners. Webster is just one of many such consultants.

"When I started eight years ago, there were just three to four of us, but lately the number has mushroomed," he says. "Apparently everyone who's served time (in prison) thinks he can be a prison consultant."

That's because demand has mushroomed, too.

"I'm getting a lot of clients who've been involved in mortgage fraud, especially from New York and Florida," says Larry Levine, the founder of Wall Street Prison Consultants, who started his company while serving a 10-year-sentence for drug dealing. "During the past year, a lot more bankers have come to me."

This summer, New York investor Bernard Madoff, the mastermind of the world’s largest investment fraud, was convicted to 150 years in prison. But unlike most of his fellow fraudsters, Bernard Madoff wasn't sent to a minimum-security prison. Despite the services of a prison consultant, he now lives at Butner Federal Correction Complex in North Carolina. (Due to the severity of his crime, he was ineligible for placement in low-security prisons.)

"Madoff is in a hopeless situation," says Levine. "He's incarcerated with people who're serving life sentences, and because they know they're not getting out they don't try to show good behaviour." Recently Madoff was involved in a fight with another inmate. "That shows what kind of access people have to Madoff," says Levine. "Next time someone will kill him. His co-conspirators will try to kill him so he doesn't reveal their involvement. It would be very easy for them to find an inmate, pay off his family on the outside, and have him stab Madoff to death."

Levine advises his clients on prison etiquette, how to get along with staff, and how to avoid being attacked by other prisoners. Demand is so high that Levine is now expanding to the UK.

But many other consultants go farther: they promise their clients a spot in one of the country's best prisons.

"We help them get spots in low-security prisons near their homes, with job training and lots of opportunities for visits by their family," says Webster.

"But all prisons are nasty places. And there are no prisons where the inmates play golf. There's just one where they mow the golf course."