Is there a more miraculous journey in contemporary sport than that undertaken by Vijay Singh, the Fiji-born ethnic Indian Sikh who, as he turned 41, an age when most golfers are declining into affluent middle age, this year won nine tournaments, including the USPGA, his third major, and more than $10 million, to become officially the best golfer in the world?

As the member of an ethnic minority in Fiji and as an unclubbable Fijian in America, Singh has spent much of his life marginalised and as an outsider. There are two prominent golfers of colour on the US tour - Singh and Tiger Woods - and they are, respectively, ranked first and second in the world in a game that for too long sought to exclude and isolate black golfers.

Yet Singh, unlike Woods, who, in his unease and isolation, is fast becoming the Michael Jackson of golf, continues to be viewed largely with suspicion even, it is said, by some of his fellow professionals. Singh is respected rather than admired, his achievement at reaching number one disparaged rather than celebrated. Oh, he is number one only because he plays so many tournaments, they say, and because the new equipment - allied to the natural advantages of his height and strength - allows him to hit the ball so far.

How to explain this? First, Singh is a true obsessive, a fanatic even. Golf, it seems, is everything to him: his life, his work. He practises harder than any other major player on the US tour. When he is not playing, he returns to his Florida base to practise: his swing, his stance. His wife has complained about his dedication and his attention to detail - she cannot drag him from the range. Steve Elkington, who knows Singh from when they played together as young men in Australia, speaks of his ‘mindless’ devotion to practice. Whenever he arrives at a new hotel, Singh immediately rearranges the furniture in his room so that he can refine his swing and his putting stroke.

The second reason for the breeze of unpopularity that continues to buffet Singh is that in 1985 he was accused of cheating and was banned from the Asian tour for two years. What happened was that Singh was found guilty of altering his scorecard at the Indonesian Open. He says that he did not do it, that someone - not him - made a genuine and honest error. Whatever the truth of the incident, and whoever was culpable, the card was altered and Singh was banned. From there, for two years, he retreated to a remote golf club in Borneo, where, earning £25 per week, he lived and gave golf lessons. That period of personal and professional exile was, you suspect, the making of the man. ‘That really was the lowest point of my life,’ Singh has said. ‘It never occurred to me out there in the jungle and out of competitive golf that one day I would reach the top. But then I knew that I had nowhere to go but up. So every day for two years I taught golf and hit practice golf balls.’

He has continued to hit practice golf balls ever since, travelling the world, winning tournaments in Africa, Asia and in Europe - until, at last, he won a place on the US tour and began his relentless pursuit of the highest honours in the game.

What is Singh like? Who are his friends? What does he think about when he is not thinking about golf? It is difficult to answer these questions, because Singh has an uneasy relationship with journalists: he does not trust them and instead of answering questions about himself he would rather play competitive golf. Or at the very least practise.

How long can he remain at number one? Can he continue to improve? Of any other golfer you would say that, at 41, the best is behind him. But with Singh, this complex, private man who once worked as a bouncer at an Edinburgh night club as he tried and failed to qualify for the Open, you would have to say that anything is possible.

Nor is he likely one morning to wake up and decide, as David Duval did, that golf is meaningless, little more than an exercise in futility. Because golf for Singh can never be meaningless: it is the means through which he remade himself, the means through which he pulled himself out of that jungle retreat in Borneo and on into a world of unimagined riches and achievement. There won’t be any stopping him next year.