Until now. An Evening Standard investigation into the death of the two Britons indicates another explanation, one which the Monte Carlo police may find far less appealing. In this version of events - supported by new evidence of Stephenson's business dealings in the last months of his life - there was not one murder but two. Our investigation suggests that as Stephenson's game unravelled, powerful figures decided he had to pay the ultimate price for failing to meet his obligations. Angela - his bubbly, devoted partner for more than 10 years before their wedding in May - simply got in the way.

The story begins, not among the palm trees and yachts of Monte Carlo, but in the English countryside. Stephenson grew up among the farms and country houses of the shires, gaining a reputation as an amateur jockey in his youth, and adopting the personal style and habits of an English country gentleman.

He presented a gruff, rather brooding appearance, but he was not without wit and charm and had many friends among the members of his generation who might have been called the county set.

One good friend was George Windsor Clive, owner of a highly successful real estate brokerage, specialising in country and equestrian properties. In 1987, Mr Windsor Clive took Stephenson on as a partner and they worked together for five years. Towards the end of this period, Stephenson began to develop a fascination for the explosion of money in the former Soviet Union. As Russian biznizmen poured into Europe, many quite literally clutching suitcases stuffed with dollars, Stephenson saw an opportunity.

"He became obsessed with the Russians," Mr Windsor Clive recalled. "He was operating in the South of France, spending vast amounts, which the deals, frankly, couldn't justify. Christopher was a brilliant deal-maker. But this business with the Russians was not working out, in my view.

"He had a place in Monte Carlo and was buying properties for his Russian clients down there. I really didn't feel comfortable about the way it was working out and I said, 'You keep them and I'll keep the rest'."

It was an offer Stephenson accepted with enthusiasm. The Russian fascination for the glamour of Monte Carlo and the Cote d'Azur presented vast opportunities, he believed. But there were also grave dangers. A lot of the money finding its way to the upscale property developments on the Mediterranean was taken there by gangsters. For these members of the Moscow mafia, business disputes often ended in a hail of bullets.

Stephenson knew all this, but in the end he had no choice. He had made a lot of money out of the Russians, enough to buy a flat in Lowndes Street in Knightsbridge and a country house in East Garston in Berkshire.

For years, his old friends would see him at Ascot and Cheltenham, looking for all the world like the wellheeled entrepreneur most believed him to be.

He talked about his dealings with the fabulously wealthy royal family of Brunei, and most people assumed he was doing rather well. Others were not so sure.

Lambourn-based racehorse trainer Charlie Egerton, an old acquaintance, recalled: "For a man as close to the Brunei millions as he claimed, he was very slow to put his hand in his own pocket." Another who did business with him said it took two years to get him to pay a bill for Pounds 800.

It did not match the profile of a man with business links to one of the world's richest families. And for good reason.

Our investigation reveals that Stephenson was in deep trouble financially.

He had resorted to passing corporate secrets he managed to glean from his extensive list of contacts to Kroll, the private investigation firm.

Former corporate investigator Ralph Ward-Jackson said: "He was a charming old rogue who was very useful to us." But Stephenson was becoming more and more desperate to pull off a big deal. He was namedropping to try to impress potential backers in his various schemes, claiming friendship with - among others - the Bahamas-based billionaire currency dealer Joseph Lewis, the British property tycoon Elliott Bernerd and Roddie Fleming, of the eponymous banking dynasty.

But it was his claim of a connection to the Sultan of Brunei's family that showed just how far he was prepared to go to make some big money.

He did once do business with Brunei interests, but there were no active links, as the London accountancy firm, Ernst and Young, was to discover to its cost.

Stephenson hired the firm to work on a proposed deal to buy out the company that owns Wentworth golf course. He made the arrangement through a Liechtenstein-based company called the Qatif Finance Establishment and told Ernst and Young that the firm was owned by the Brunei royal family.

In fact, it had been set up by him.

In 2002, Ernst and Young issued a writ against Stephenson in the High Court, claiming he had misled them into believing they were undertaking work for the Sultan's family.

They wanted payment and damages of more than Pounds 100,000.

IT WAS money that Stephenson simply didn't have. With the threat of bankruptcy looming, his drinking became even heavier than usual.

Charlie Egerton, who last saw him in Monte Carlo last April when Chelsea played Monaco, said: "He was down on his luck. He was pissed most of the time and I had the feeling that, like a lot of people who are drinking to excess, he was hiding behind the booze."

The big deal that Stephenson hoped would allow him to live out his life in luxury had eluded him, but he had one last ace up his elegantly tailored sleeve. Stephenson had worked hard at cultivating his Russian contacts - in December 2000 he was appointed a director of The Friends of St Petersburg Philharmonic Orchestra, a role that allowed him easy access to very influential expatriate Russians.

Through his Russian friends, he came to know an official in the Foreign Ministry in Moscow.

Stephenson was a secretive man, but he told his business associates that this official was involved in disposing of unwanted diplomatic buildings owned by Russian embassies across the world.

Stephenson began offering investors a deal in which they would put up money to buy these buildings at a favourable price, arranged by his ministry contact. The properties would then be sold at a sizeable profit. It is not known who, precisely, put up money for the scheme, but some did.

The innermost secrets of the scheme died with Stephenson, but it appears his man in Moscow never came up with the diplomatic properties that had been promised in, among other places, London, Athens, Rome and Washington.

However, substantial sums had been paid out in bribes, it was believed, and when Stephenson's investors demanded their money back, he couldn't pay.

Like others, Charlie Egerton knew of his plight. "Basically, he had taken a lot of money from a lot of people for the Russian embassies deal and he couldn't return it," Mr Egerton said.

He then appears to have become frightened. He called in two sets of spare keys to his flat, held by the concierge and his cleaning woman.