Dick Seaman was a British sporting hero. Of a very particular sort. He died, terribly burnt, some hours after he had crashed his formidably fast silver car into a tree when leading the Belgian Grand Prix in heavy rain at Spa on 25 June 1939. Britain would declare war on Germany on 3 September. Seaman had been driving for the official Mercedes-Benz team. Adolf Hitler had personally approved his selection.

The previous year he had won the German Grand Prix in front of a fervently patriotic crowd, 300,000 strong, at Nurburgring. Garlanded in a giant laurel wreath, he took the podium and gave a Nazi salute. Not once, but twice. His friend, George Monkhouse, an engineer for Kodak and a celebrated trackside photographer, was there to record the scene. Perhaps it had been a rather half-hearted salute and Dick had, it's true, whispered down to John Dugdale of the Autocar: 'I wish it had been a British car'; but he may well have said this out of courtesy. There was no British Grand Prix team at the time. No British car could get anywhere near the Reich's mighty Mercedes-Benzes and Auto-Unions. As a sportsman, and a young man who chafed against incompetence, Dick was proud of the Germans' success. It might even encourage the chaps back in Blighty to get a grip.

'England is becoming a pretty good joke,' he had written to Monkhouse a few months earlier, 'especially in the Fascist countries, for her flannel-footed behaviour politically, and we are rather looked upon as a lot of decadent old women.'

At the time of his death, Seaman was 26 years old, tall, fit, manly and anything but decadent. He drank moderately, spoke German rather well, was married to a beautiful young German, Erica Popp, daughter of the head of BMW, and lived in the Fatherland. He admired the 'electrifying' Hitler, while insisting that politics and sport did not mix, and, blithely imagined himself racing at the British Grand Prix on 30 September 1939 at Donington. His funeral was held in London on 30 June 1939: Hitler sent an enormous wreath.

Two years earlier and just before he signed with Alfred Neubauer's legendary motor racing team, Seaman had written to his mother from Bavaria: 'Hitler stands no nonsense. He won't have any slackers about. Everybody has got to work. Consequently he has remade and reorganised the country, and that is why they believe in him and rally round him. It's about time Hitler took over Austria too, and made them sit up and pull themselves together. The dirt and squalor and laziness in the country are beyond words. Why, there are men there who ask nothing better of life than to sit about all day over one cup of coffee in a cafe!'

'How impressive it is,' replied his mother, the formidable Lilian Beattie-Seaman, 'to see the way in which Herr Hitler stands no nonsense from shirkers, wastrels and communists.'

Nobody could accuse Dick Seaman of shirking, nor of left-wing sympathies. Whether skiing, shooting, flying, racing or out on the town, he lived life in the very fastest lane, at anything up to 180mph on the straights. He might have been a member of the right-wing Carlton Club, but he was not a card-carrying Nazi. He might stand accused of being self-centred, ambitious, naive and all but blind to the traumatic events shaping and closing in on his brief life. Yet, his was an almost unwitting Faustian pact with Mercedes-Benz, and, by extension, with Hitler and Nazi Germany. He was the only Englishman to power around the race tracks of Europe and the US with a swastika on his tail.

There had been moments, it is true, in the spring of 1939 when he had wondered if he should abandon his lavish life in Germany and return to Britain. He had written to his friend and mentor, Lord Howe, a fellow racing driver. Howe replied that there was nothing really to worry about and that he would he would be doing everyone a favour by maintaining friendly relations with the Germans. The Germans had come to admire the handsome young hero.

That Dick Seaman was honest and brave should never be in doubt. On his deathbed, and despite searing pain, he told Rudi Uhlenhaut, chief engineer of the Mercedes-Benz racing team: 'I was going too fast for the conditions - it was entirely my own fault - I am sorry.' But, then, this might have been Seaman's epitaph. He had truly been going too fast for the conditions and ended up doing more for Nazi Germany than he did for his own country.

How had this extraordinary turn of events come about? Seaman was not the only foreign driver racing for the greater glory of the Third Reich. There were the Italians, Luigi Fagioli and Achille Varzi, although they came from a Fascist country that was to sign an infamous Pact of Steel with Nazi Germany in May 1939. And, there was the French star, Louis Chiron. Since his youth, Seaman had been driven on by a dream of winning a European grand prix. The last Englishman to have done that before Dick himself took the chequered flag at Nurburgring on 24 June 1938, had been Major (later Sir) Henry Segrave in a works Sunbeam at Tours in 1923.

Seaman was very different from most of his British contemporaries. He was well travelled and had none of the fear nor disapproval of the Continent expressed in the writings of all too many British writers of the Twenties and Thirties. He felt quite at home in France, Italy and Germany. A young man who asked his mother for a country house of his own for his twentieth birthday present, and got it, was always going to be pretty sure of himself.

Richard John Seaman-Beattie was born at Aldingbourne House, near Chichester on 3 February 1913. Silver spoons hardly came into the equation: his father, William Beattie-Seaman, a wealthy 52-year-old businessman from a grand Scottish background, immediately set up two trust funds for the boy, who was always known as Dick. One was for £100,000, the other for £75,000; in today's terms, approximately £6.5 million and £4.5m. The one proviso was that Dick would have to wait until he was 27 to cash in. He was 26 years and 5 months old when he died.

His father, despite a dicky heart, had married a second time, in 1911. The lucky lady was Lilian Graham Pearce, described by Doug Nye and Geoffey Goddard, authors of Dick & George: the Seaman-Monkhouse Letters, 1936-1939' as 'a ferociously pompous grande dame of absolutely the stiffest corset', and 'a monumental snob' to boot. Lilian found Aldingbourne House insufficiently grand and insisted on a move to Kentwell Hall, near Long Melford, Suffolk in 1915. This truly grand Elizabethan house was very nearly flattened during a Zeppelin raid the following October. Plucky young Dick declared: 'These awful Germans! You wait 'til I'm grown up. I'll put them all through the iron trapdoor into the moat.' But he became their champion instead.

Lilian moved her darling only child to 3, Ennismore Gardens, Prince's Gate, London, although Dick was always happiest out of town. Prep school in Broadstairs was followed by Rugby where Dick coasted academically and avoided team games. He was regarded as a confident individualist and even a bit of a rebel. A dandy, too; he liked to think of himself as Bertie Wooster with an edge. He had to cram his exams to get a place at Trinity College, Cambridge, yet even then he was spending more time eventing with his new Riley sports car than studying. He came second in his first speed competition at Shelsley Walsh hill climb in 1931; first place went to another Riley driver, Whitney Willard Straight, an American millionaire and Cambridge undergraduate. Straight kept a plane at Cambridge; Dick learnt to fly and the two young speed-merchants hopped from race to race during term-time.

Dick wrote off his new Bugatti, ploughing into the side of a bus at Victoria Coach Station. Lilian thought the country would do him good after all and bought him Pull Court, Worcestershire (a school today) for his twentieth birthday. William and Lilian, having, by now, spoilt their boy rotten, still had hope that he would become a barrister and a Tory MP. Instead, Dick joined Whitney Straight's new racing team. On 26 August 1934, he won his first race, the Prix de Berne, a junior grand prix at the Bremgarten forest circuit, in his supercharged MG K3 Magnette. Elated, he then watched the Swiss Grand Prix on the same circuit: his team-mate, Hugh Hamilton, drove his Maserati 8CM into a tree and was killed. He had been dicing with the extraordinary new German machines from Auto-Union and Mercedes-Benz.

Back in London, Lilian did her best to persuade Dick to abandon racing. It was too dangerous, she said. So, she bought him a plane - a De Havilland Gipsy Moth III for £555 - in the hope of diverting his attention. Things looked good for Dick's parents when Whitney Straight, planning his wedding, announced he was packing up racing. Even so, the two young men flew off to South Africa - a 13-day trip either way - in Straight's De Havilland Dragon Rapide to take part in the first South African Grand Prix at East London. This was altogether too much for William Seaman-Beattie. Waiting anxiously for Dick's return, he threatened to cut off his inheritance; but a sudden heart failure did for him before he was able to do so. Dick persuaded his newly-widowed mother to buy him a 1.5-litre works ERA racer for £1,700.

The car proved to be a poorly rebuilt spare. Dick got nowhere with it. Furious, he resigned and with Lilian's generous purse, set up his own team with workshops in the garages of Ennismore Gardens. With an ERA of his own prepared by Giulio Ramponi, the former Scuderia Ferrari Alfa-Romeo and Whitney Straight engineer, Dick won the 1935 Prix de Berne at 82mph, trouncing Raymond Mays, ERA's official driver. This was sweet revenge.

Having won a hat-trick of European races in the black ERA, Dick had Rampoli prepare a straight-8 Delage special and won the 1936 RAC International Light Car Race on the Isle of Man. The British press made hay with the story of the Cambridge student who came from nowhere and trounced the opposition with a tuned-up banger.

This was not quite the truth. Dick, though, was a force to be reckoned with, Ramponi a fine engineer and, watching the young driver's swift progress from the sidelines, was Alfred Neubauer, head of the Mercedes-Benz racing team. At first, Lilian tried to hide Neubauer's telegram when it arrived addressed 'Seaman - Ennismore Gardens'; but, perhaps, she was secretly relieved. She had spent £20,000 - £2m today - on Dick's racing career. Now, it looked as if Mercedes-Benz would be footing the bill. Dick's victory at the 1936 Grand Prix at Donington, in a borrowed straight-8 Maserati 8CM, had convinced Neubauer that this was the young blood his team needed.

The telegram invited Dick for trials with Mercedes-Benz at Monza. He was off like a shot. Within weeks he was writing to his Cambridge chum, George Monkhouse, from the splendour of Milan's Hotel Principe & Savoia. Come on out and photograph for Mercedes, George. George did come, in July 1937, pounding across Europe in his beloved 4.5-litre Bentley accompanied by his prized cameras. Before George arrived, Dick had crashed a 180mph Mercedes-Benz W125 into a tree at Monza and cracked a knee-cap.

George came to Germany to cover the grand prix. It was, as his photographs prove, a magnificent sight. Five silver 6.1-litre V16 C-Type Auto-Unions were lined up against five silver 5.66-litre straight-8 Mercedes-Benz W125s, two, blood-red Scuderia Ferrari straight-eight Alfa-Romeos and a pack of private entrants. It was a fast and furious race. On the seventh lap, the Auto Union of Ernest 'Titch' von Delius crashed into Dick's Mercedes at 170mph; Von Delius died later that day. Dick was thrown from his car, suffering burns, a broken nose, thumb, wrist and arm. He was to require plastic surgery. While he was recovering, the German cars made their awesome debut in Britain, and Dick showed the Nazi-friendly Duke and Duchess of Windsor around the Mercedes-Benz factory in Stuttgart.

And, then, at a party hosted by BMW for British guests at the Preysing Palace restaurant next door to the Burgerbrakeller from which Hitler had launched his failed Munich putsch in 1923, Dick met the pretty and pampered Erica Popp.

This was on 15 June 1938. Nine days later, Dick powered a V12 Mercedes-Benz 154 to victory at Nurburgring. It had been a white-knuckled ride from beginning to end. Lapping at an average 83.71mph for three hours, 51 minutes and 46.1 seconds, Seaman had given his team-mates, let alone his rivals, more than a run for their money. 'Der Englander' was viewed with increasing concern by Neubauer's top two drivers, the snobbish Rudolf Caracciola and the Junker, Manfred von Brauchitsch.

In every sense, Germany had Dick Seaman in its grasp. Erica was thrilled. Now she got to meet Lilian who came over to Germany. Lilian, despite her reservations concerning Dick's choice of career, was overwhelmed by the newsreels which she watched, over and over again, showing Dick's victory, Dick receiving his laurel-wreath, and Dick saluting, as the oompah bands played 'Deutschland Über Alles' followed by 'God Save the King'. The official broadcast ended with portraits of Dick, the Führer and King George VI. 'I thought,' wrote Lilian, 'there will be no war. The German people are a friendly nation. They do not want war...'

Lilian was entranced by Erica, too; she thought her a 'goddess', and was impressed when she learnt this fine specimen of the master race was the daughter of not just one of the Reich's most successful industrialists, but an aristocrat to boot. He was also a close friend of Göring, Von Ribbentrop and Hitler. And, for a moment, the threat of war appeared to pass. Erica's father consented to the marriage on 14 September. On 16 September, Neville Chamberlain, the Prime Minister, met Hitler in Munich. He returned to London believing he had negotiated peace in his time. He had done no such thing.

Back in Ennismore Gardens, Lilian began to have misgivings. Hitler did mean war. How could her beloved Dick marry a German citizen? How could she have German grandchildren? What would the neighbours think when the bombs dropped on Knightsbridge as once they had so very nearly done on Lilian and Dick at Kentwell Hall?

Despite Lilian's objection, Dick and Erica were married, at Caxton Hall, Westminster on 7 December 1938. It was, because of international as well as family politics, a low-key occasion. The happy couple took off to the Bavarian and Austrian Alps where they spent the winter skiing. Dick signed a new contract for the 1939 season, his third with Mercedes-Benz. It was to be his last.

The year began auspiciously, as far as Dick, Neubauer and the racing team were concerned. The latest cars were unveiled by Hitler at a grandiloquent Berlin Motor Show in February. 'At the end of his 17-minute speech,' Dick wrote to George, 'plush curtains at his back swept aside, disclosing to a fanfare of brass instruments, the main exhibition hall beyond. In fact, I doubt if Cecil B De Mille could have done it much better himself.'

There is a beautiful and haunting photograph in Nye & Goddard's magisterial book of Dick and Erica sitting together just after lunch in a restaurant at Spa in Belgium on 25 June 1939. Erica is lighting a cigarette for Dick. Only Hollywood, in the guise of Bogart and Bergman in Casablanca was to match them in the glamour stakes of those truly noir years. This is their last lunch together. A few hours later, on the twenty-second lap of the Belgian Grand Prix, Dick would crash his furiously fast W154. 'I am afraid you must go the cinema alone after all,' Dick told a trembling Erica, before he died. They both loved what Dick called 'the flicks'. And, this was 'The End'. After the war, Erica went on to marry first one American millionaire and then another. She became a US citizen and died in Florida in 1990.

As the world prepared for war, Seaman's death was reported in Britain in a couple of paragraphs in the Daily Telegraph. Entirely his own fault, he would have said. He lives on, though, in old newsreels and in the fine photographs taken of him in action by George Monkhouse. George published his handsome Motor Racing with Mercedes-Benz before the war. In 1947 he met his future wife, Constance. By chance, she was working as secretary to the chairman of the new British Overseas Aircraft Corporation, Air Commodore Whitney Straight, MC, DFC. Straight had married an Englishwoman in 1935, taken British nationality and fought as a Hurricane pilot during the Battle of Britain. He escaped twice from behind German lines. He later worked for Rolls-Royce whose aero-engines played a major role in bringing down not just Mercedes-Benz-powered German fighters, but the Nazi regime itself. What, it is hard not to ask, did Straight ultimately make of his former friend and team-mate, Dick Seaman, a very particular Nazi sporting hero?

· 'Dick & George: The Seaman-Monkhouse Letters, 1936 - 1939' by Doug Nye, published by Palawan Press is limited to 1,500 copies and is available in two editions by mail order. The clothbound edition with dust jacket costs £135 plus delivery. The Moroccan-leather-bound edition, limited to 50 numbered copies, is encased in a silver buckram drop-back solander box (£750 inclusive of delivery). Tel 020 7371 3060 or visit www.palawan.co.uk (email: info@palawan.co.uk)