BACK ON a bright, showery morning last March, a week before he caught the plane to Sao Paulo for the season's first grand prix, Ross Brawn leaned back in the chair of his office at the Benetton racing car factory in the Oxfordshire countryside, blinked behind his big round spectacles and smiled his owlish smile as he considered the question of complying with Formula One's new ban on computerised driver aids.

Do you feel, Benetton's design chief was being asked, that you're likely to stray into any of these new grey areas of illegality?

'I don't think so, no. I'm fairly confident we're kosher.'

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What about the other teams?

'Well, so much depends on what results people are getting. Ferrari, for instance, have a new front suspension system. Some people think it's legal, others don't. If they started to run away with the races, I'm sure the other teams would become more vociferous in their objections. But if they aren't competitive, people will tend to overlook it.'

Ten days later, nobody was thinking about Ferrari's front suspension system as Ross Brawn stood, still smiling owlishly, on the fringes of the festivities in the Benetton pit at Interlagos, waiting for Michael Schumacher to return from the podium and join the team in a glass of champagne to celebrate a conclusive victory.

No, the Ferrari suspension was forgotten. But up and down the pit lane, other teams were thinking about the way Schumacher had used Brawn's new car to blow away the overwhelming pre-season favourite, Ayrton Senna and his Williams-Renault. Ten races, six more wins, several technical examinations, one mid-race row in the stewards' office, two disqualifications, a fuel fire, two disciplinary tribunals and a driver suspension later, no one in Formula One is thinking about much else.

THE FIRST to face the problem was Senna. When he couldn't shake Schumacher off his tail in the early laps at Sao Paulo, he knew he had a problem.

The cars were less than a second apart when they made their first tyre-and-fuel stops. Schumacher came out just ahead, with a lead he never relinquished; a second pit stop gave him another couple of seconds. Senna's pursuit was typically exhilarating to watch, as the the gap closed lap by lap. But he was having to try harder than anyone knew. With 15 laps to go he lost control and spun off.

At the next race, the Pacific Grand Prix, Schumacher sprinted away from the line and watched in his mirrors as a harassed Senna crashed at the first corner. And at Imola, in late May, Senna was trying desperately to stay ahead of Schumacher when, for reasons as yet unexplained, he ran off the road at Tamburello and died.

By this time, a lot of other people were thinking hard about the Benetton-Ford. In mid-July, when Schumacher arrived at Silverstone for the British Grand Prix, he had six wins and one second place from seven races, and the championship was looking like the biggest walkover of all time. It was clear that Benetton had the best-packaged racing car, and that Schumacher possessed the talent to exploit it. His post-race embrace with Flavio Briatore, the team's extrovert managing director, was by now a regular feature of the TV coverage. But at Silverstone the season went sour for Benetton, just as it already had for so many others.

First, Schumacher broke the rules by overtaking Damon Hill, the pole-position man, on the parade lap - a blatant attempt to establish a psychological advantage in front of Hill's home crowd. Then Schumacher failed to stop immediately when the stewards showed him the black flag. The suspicion - strenuously denied - was that his team had radioed him to stay out while Briatore argued the toss with the stewards. His own excuse - that he'd failed to see the flag - was disbelieved by a tribunal of the FIA, the international motor sport federation. He was suspended for two races, and the team was fined dollars 500,000.

Shortly after Silverstone, the FIA issued the results of analyses of the computer control systems of the Ferrari, McLaren and Benetton teams, taken after the Imola race. Ferrari had co-operated, and were clean. The two British-based outfits, however, were fined dollars 100,000 each for attempting to deny the FIA's inspectors access to the codes which give access to their computer programmes.

When the inspectors got into the Benetton computers, they discovered a hidden programme, and it was dynamite: a programme called Launch Control, which allowed Schumacher to make perfect starts merely by flooring the throttle, the computer then taking over to ensure that the car reached the first corner with no wasteful wheelspin. Legal in 1993 but outlawed by the new regulations, the programme was still there - although now it had been concealed. To find it you had to call up the software's menu of programmes, scroll down beyond the bottom line, select an apparently blank line, press a secret key - and, hey presto, without anything showing on the screen, Launch Control was ready for action.

Brawn's claim that the system had not been used during the 1994 season could neither be proved nor disproved; the FIA's decision to publicise their findings suggested that they had their suspicions. After all, if Launch Control was now redundant, why had it had been left sitting in the software? Because, the Benetton people said, the task of isolating and removing it was one of impossible complexity. (The concealment, they added, was simply to prevent somebody switching it on by mistake.)

'That's enough to make me believe they were cheating,' one computer specialist with another team told me last week. 'Look, we purged our own software of all the illegal systems during the winter. I did it myself. It took me two days. That's all. Perfectly straightforward. And the fact that they disguised it was very suspicious.'

In the very next race, at Hockenheim, Schumacher suffered his first retirement of the season in front of his home crowd. And Jos Verstappen's car briefly disappeared inside a fireball when fuel spurted out of a hose and ignited on the hot engine - the result, said the equipment's manufacturers, of Benetton's illicit removal of a filter, by which they speeded up the fuel-flow (perhaps saving a second per stop, which Senna would have been interested to hear) but which had allowed a piece of dirt to jam a valve open. In their own defence, Benetton claimed that the modification had been verbally agreed with the FIA's technical observer, and commissioned an independent investigation which, unsurprisingly, exonerated them.

While Benetton prepared to answer the charges at a formal hearing, Schumacher restored the status quo by racing to victory in Hungary in mid-August. Last weekend, however, came the most serious incident of all - when the German, after taking the chequered flag in Belgium, found himself disqualified for wearing down a section of the wooden 'skidblock' - a wooden plank bolted to the bottom of the car, introduced by the FIA in midseason to increase ground clearance and thereby slow the cars down by reducing the aerodynamic effect.

To some people, the very existence of this primitive device is a ludicrous addition to a sport that exists on the leading edge of high technology. To others, it is an elegantly simple solution to a complex problem. But the debate over the nature of Benetton's sin - how the wear had been caused, if indeed it was wear at all rather than intentional reshaping aimed at restoring some of the lost ground effect at the front end of the car - showed that nothing in motor racing is as simple as that.

The team's instant claim that the wear was caused when Schumacher had spun over a kerb was quickly dismissed by the videotape of the race, undermining their innocence. Once again the weakness of a Benetton excuse had allowed cynics to call their whole sporting ethos into question.

THE STYLE of the Benetton team is a product of the combination of two very different men, linked by a common addiction to power and success.

Flavio Briatore is a rather voluptuously elegant figure who was put in control of the team in 1989. According to Benetton's publicity, he 'believes in youth, strength and excitement'; by his own admission, he neither knows nor cares about the tradition or technology of motor racing. To him it is part show, part business.

By contrast, Tom Walkinshaw is elbow-deep in engine oil. A tough Scot, he bought a share of the Benetton team in 1991, brought in Ross Brawn to head a new design team, and began to apply his rigorous standards of organisation. Walkinshaw is a motor-racing man through and through, but he is not in the sport for the fun of it.

Together, they have pooled their wits and ruthlessness to overtake teams with deeper traditions and greater resources. It may or may not be too fanciful to suggest that their reputation for shock tactics - such as the coup with which they swiped Schumacher from Jordan in 1991, or the shameless campaign with which they persuaded Renault to commit bigamy next season by supplying Benetton as well as Williams with their best engines - are consistent with the approach of a parent company which markets clothes through images ranging from the iconoclastic to the distressing.

All racing-car designers push the rules to the limit, but the evidence suggests that Benetton's personnel may have become a little overheated in their search for an advantage. It's not surprising to hear their rivals grabbing the chance to cast aspersions. 'When you build a car on the threshold of legality,' said Niki Lauda, a consultant to Ferrari, last week, 'which Benetton has apparently done all year long, and you get caught out again and again, it's simply not right.'

Last week in Paris, Schumacher lost his appeal against the two-race disqualification. So instead of having the title wrapped up early, he may find himself going into the final three races only a single point ahead of Damon Hill. In Paris on Wednesday, Briatore and Brawn will appeal against the Belgian disqualification and have to face questions about the refuelling equipment. If they fail to convince the jury, and if the FIA's president, Max Mosley, lives up to his promise of inflicting Draconian punishments, they could be out of the constructors' championship.

The Benetton company is one of only two major sports sponsors with a positive appetite for bad publicity (Nike, exploiting the behaviour of Andre Agassi and Eric Cantona, being the second). But there are already rumours that the team's other sponsors have get-out clauses in their contracts, and that their number one driver, fed up with it all, may start next season in a Williams, with Renault's blessing.

Whatever happens, it may now be too late to salvage a season that was supposed to witness the rebirth of an open, competitive Formula One but instead found itself plunged into gloom and chaos.

THE MAIN PLAYERS: PROTAGONISTS IN THE BENETTON SAGA

FLAVIO BRIATORE

Managing director, Benetton

Looks like motor racing's answer to Marcello Mastroianni, with his smouldering eyes and elegant clothes, but wears his emotions on his tanned face too readily to play poker in the same league as Walkinshaw and Brawn (see below). No one can quite be certain of Briatore's background, but photos in his London flat show him with all manner of famous faces, from the disgraced former presidential candidate Gary Hart to the actress Uma Thurman. All these images, however, date from his arrival in Formula One in 1989. Before then, details about his antecedents are scarce. A maverick who likes to cut a dash, he is regarded with suspicion by some of his peers because he is a businessman rather than a racer. He had a blazing row with Max Mosley over rule changes at the Spanish Grand Prix in May, which has triggered something of a feud.

TOM WALKINSHAW

Engineering director,

Benetton

If men were machines, Walkinshaw would be a bulldozer. The blunt 45-year-old Scot is powerfully built and, though not renowned for his ability to deal with people, has a loyal following among the engineers at Benetton. Since his arrival at Benetton in July 1991, his reorganisation of the technical functions has laid the foundation for its present success. Single- minded, he is no stranger to controversy, nor arguments over rule interpretations.

ROSS BRAWN

Technical director, Benetton

The 39-year-old lives up to his name physically, but also has plenty of brains. Ambitious and smart, he is a protege of Walkinshaw's. He cut his engineering teeth with Williams before switching to Arrows. After that he designed Jaguar sports cars in the late Eighties. A typical no-nonsense engineer, who is responsible for the legality of the Benetton cars, he is adept at conveying complex technical points to laymen.

JOANN VILLADELPRAT

Team race manager, Benetton

A quiet Spaniard, 38, who has experience with a number of top teams, including McLaren. He is said to have been the man who took the decision to remove the filter from the Benetton refuelling system, the absence of which was discovered by investigators after the fire which engulfed Jos Verstappen's car at Hockenheim. The team claim that they had authorisation from the FIA's Charlie Whiting to do so.

MICHAEL SCHUMACHER

No 1 driver, Benetton

A champion in karting, junior league motor racing, German Formula Three and World Sportscar racing, and apparently heading relentlessly towards the ultimate prize until his recent reversals of fortune. With the death of Ayrton Senna, the 25-year-old, who was poached by Benetton in 1991 immediately after a highly successful debut for Jordan, is now unquestionably the driver by whom the others are judged. Calm, almost machine-like, Schumacher is frighteningly quick and has a sound grasp of technical aspects.

BERNIE ECCLESTONE

President of Foca

The tsar of Formula One, Ecclestone is an iceberg. What you see is only a small proportion of his character. A racer through and through, the 62- year-old loves doing the deals that keep the wheels of Formula One revolving. He can be uncompromising and occasionally walks a tightrope between his dual roles of vice-president of marketing for the FIA and president of the Formula One Constructors' Association. He is the sport's powerbroker and, effectively, calls the shots. Nothing happens in Formula One that he does not know about.

MAX MOSLEY

President, FIA

The 52-year-old son of the controversial politician Sir Oswald, and a trained barrister. Turned instead to motor racing, and, after low-key career behind the wheel, he founded March Engineering in 1969 with the designer Robin Herd. Urbane and articulate, his antipathy to Briatore was exacerbated by their row in Spain during which Briatore suggested that Mosley would be better off gardening on race weekends. He is said to harbour political ambitions in Europe, and may see presidency of the FIA as a useful stepping-stone.

CHARLIE WHITING

Technical delegate, FIA

A chipper 42-year-old from south London, Whiting is the archetypal poacher turned gamekeeper. As the former chief mechanic at Brabham during Nelson Piquet's greatest years, he knows everything there is to know about maximising cars within the rules. Now he is a formidable man to try to slip anything by. He detected the existence of the 'launch control' starting system on the Benetton, the absence of the fuel filter, and he measured the plank on Schumacher's car after the Belgian GP. He is a resilient type who can put up with occasional unpopularity.

(Photographs omitted)