His life has unfolded like a tragi-comic saga of twists and turns, of contradictions, of shifting from one extreme to another and of illusion versus reality.

It started out so promisingly, as a 1990s version of a classic rags-to-riches tale.

But Leeson has added further chapters onto the story, living an extraordinary rollercoaster of rags-to-riches-to-rags-again - and, potentially, -to-riches again.

Now the world is waiting for the sequel.

Lisa, who was an adoring wife before the marriage ended

Leeson was the working class son of a plasterer from a Watford council estate, who failed his final maths exam and left school with a mere handful of qualifications.

Nonetheless, in the early 1980s, he landed a job as a clerk with royal bank Coutts, followed by a string of jobs with other banks, ending up with Barings, where he quickly made an impression and was promoted to the trading floor.

Before long, he was appointed manager of a new operation in futures markets on the Singapore Monetary Exchange. Aged only 26, the whizzkid was trusted by his bosses back in London, who viewed with glee his large profits.

Leeson and his wife Lisa had it all: a salary of �50,000 with bonuses of up to �150,000, weekends in exotic places, a smart apartment and frequent parties. And they were very much in love.

Beginning of the end

By 1993, he had made more than �10m - about 10% of Barings's total profit that year.

He had a knack for predicting fleeting price changes in the Far Eastern markets and was lauded as Barings's top trader.

Leeson portrayed behind bars in the film Rogue Trader

He enjoyed the thrill of speculating in vast sums of money and as team leader, did the office book-keeping.

But in 1994, a mistake by an inexperienced team member sparked the chain of events which led to his disgrace.

The woman lost �20,000. He covered up by creating an "error account", 88888, - of which London was unaware.

Then, as the markets turned against him, accelerated by the economic impact of the Kobe earthquake, he realised he could hide every loss in this account, so that his office would always appear in profit.

Jail life

As the losses grew, Leeson requested extra funds to continue trading, hoping to extricate himself from the mess by more deals, but actually being sucked deeper into a hole.

Even though he and Lisa were close, he kept details of the crisis from his wife.

In February 1995, Baring's bosses uncovered �850m losses.

Leeson knew the game was up - and confessed all to Lisa. He guessed he would be jailed for the fraud - and, in the hope of his being locked up in the UK rather than the Far East, the couple went on the run. Leeson was arrested in Frankfurt, extradited to Singapore - and jailed for six and a half years. He has served nearly four, being freed for good behaviour.

In jail, he is said to have exercised vigorously and "found God".

Marriage and health collapse

The fortunes of Leeson's personal life mirror almost as starkly the peaks and troughs of his career. Not only has his lifestyle been shattered, his life itself is now in question.

Leeson is said to have "found God" in his Singapore ail

As if in a soap story, Lisa got a job as an air hostess to be able to visit him regularly. She even helped him write his book, Rogue Trader.

Their marriage survived the strain of being apart. But what Lisa could not abide were his revelations of his infidelity with Geisha girls, and she divorced him. Her remarriage - to another City trader - served to further knock his spirit. He grew very depressed at losing his once-devoted wife.

Within months, Leeson was diagnosed as suffering from cancer, the disease which had killed his mother.

After surgery, he is in remission. At the age of 32, doctors have given him a 70% chance of surviving more than five years.

From being a partying, good-time youngster who could abuse his body with heavy drinking, he has been reduced to a ghost of a man. His weight plummeted and most of his hair fell out from chemotherapy.

When he returns to the UK, nothing will be the same. The high life has been swept away; he is now effectively homeless and without a job.

Rich again

And yet one senses Leeson is a man who will always fight back, whatever blows are delivered to him, and turn things to his advantage.

He could receive a considerable sum from the proceeds of the film Rogue Trader, which is expected to take �25m in profit.

He has already made an estimated �50,000 from his book, and the fee for newspaper serialisation is reported to be about three times that amount.

It has also been reported that he stashed away cash before being jailed. Fellow inmates told a Sun reporter that Leeson boasted that he had �2m in secret accounts - a subject on which he is an expert.

The claim may have been merely posturing, but no-one expects Leeson having to rely on income support benefit.

Already he has bought a first-class ticket for the flight back to London.

Whether there will be an end to the surprises Leeson produces, everyone is waiting to see.