Convicted ex-Goldman PA stands ready to offer advice to Tom Hayes et al if they're found guilty

From Bernie Madoff the ponzi king, to Raj Rajaratnam, the ex-hedge fund manager imprisoned for security fraud, to Tom Hayes and the other traders pleading not-guilty to charges that they manipulated LIBOR, and the ex-JPMorgan bankers facing fraud charges for their part in the 'London Whale' scandal, investment banking has suddenly become an industry with a real risk of imprisonment.

Fortunately, help is on hand. Joyti Waswani (formerly known as Joyti De-Laurey), the ex-Goldman Sachs secretary who stole £4m from her bosses at Goldman Sachs, is working for Prison Consultants, a new business conceived to help naive white collar criminals and their families adapt to the harsh reality of life inside.

"No matter how great your defence team are, there may come a point when you need to accept that you may be be going to prison," says Waswani who was sentenced to seven years, but released after 3.5 for good behaviour. "At that point, it will really help if you have some advice from people who've been through it before."

Bankers facing impending imprisonment need to be aware that they may be targeted by other prisoners, says Waswani. "If you're well-educated and well-spoken, people will think you have money," she says. They also need to be prepared for a predictable culture shock: "A lot of people in prison can't read or write. Many of them have never really had a chance in life - I met a woman who was having her baby in prison and had been born in prison herself."

In the UK, the situation is far worse for female bankers who are imprisoned for white collar crimes, says Waswani. The country lacks a large network of open prisons for women, with the result that offenders from different categories are often locked up together. By comparison, male prisoners are more often segregated according to the nature of their crime(s). Waswani spent time in Holloway prison, a closed prison for adult women and young offenders in London. "I went in completely cold, from the police cell directly to Holloway," she says.

The worst thing about being prison, according to Waswani, is disempowerment. "The toughest thing for anyone with any intelligence is the simple fact that every ounce of responsibility is taken away from you," she says. "That's very hard and it will be even harder if you're used to working in a bank with a team of people who do what you ask."

In many ways, Waswani being at prison is like being at a rough school: "People will goad you. You need to learn prison etiquette, which is fundamentally to keep yourself to yourself and not to ask stupid questions."

Of her own crime, Waswani expresses deep repentance. "I did wrong. Now that I'm out, I would never do anything that would make me go back to prison. It's the biggest waste of life." What drove her to steal the money from her bosses at Goldman? "Everyone's in the City with the sole purpose of making money," says Waswani. "People aren't there to be altruistic - money is what drives everyone. I became a money-driven as opposed to an emotionally-driven person."

Joyti Waswani's tips for bankers who find themselves banged-up:

• Be careful what you pack - you won't be allowed most of it. Personal items like photos of children, for example, will not be permitted from the outset and must be sent in.
• Prepare for things like medical insurance covering your family members to become invalid while you're inside.
• Be ready to read. Things like newspapers are restricted in British prisons, but you have unlimited access to books.
• Use your skills to help your inmates. Many prisoners are illiterate and a lot of prison life (eg. filling in request forms, writing to relatives) involves writing. If you can help people to write, you will earn favours.
• It's not the murderers you need to watch out for - it's the prolific re-offenders. "Murderers are some of the safest people to be around in prison - they are among the least likely to re-offend. Often, if you've killed someone your whole life will be finished because of it and you'll be consumed with guilt," says Waswani. "The worst people to be around are the prolific re-offenders who might be there because of drugs or aggravated assault."