Even confirmed cynics were convinced.

Yet so widely have the seeds of doubt been sown, Murali knows some people - especially his Australian critics whose vocal objections have forced him to withdraw from Sri Lanka's current tour there - will never believe he does not consistently break Law 24.3. You will be able to make your own judgment when the Channel 4 programme is shown during the Lord's Test.

I have been fortunate enough to be a close-at-hand witness to some of the key moments in his controversial career since he made his debut 12 years ago and the Murali I know is not a cheat.

In conversation last week, after subjecting himself to the scrutiny of yet more cameras and expert analysis, Murali speaks with anger in his eyes about his continuing ordeal.

He recalls vividly the day his nightmare began, the day Darrell Hair called him for chucking on Boxing Day of the 1995 Test against Australia in front of 55,000 people at the Melbourne Cricket Ground.

'In such a big stadium where the seats are like going up straight to the sky, it looked as if the whole world was looking down on me,' he says.

'And I didn't know what for. I didn't even understand what he [Hair] was saying. At first I thought it was my feet. He didn't explain properly. To me, the ball was no different to all the others.

'Seven times in three overs he called me but he didn't call me every ball, when they were so much the same! He was treating me like I was stupid. I'm not. And meaning I was a cheat, which I didn't know how to be. I just didn't know why they were doing it. It made no sense. From where the umpire stands how could they see if my arm was bent?

'Of course afterwards, the story came out that umpire [Ross] Emerson was asked by an Australian Cricket Board official to report me well before I played in front of him. It was a horrible time, hard to cope with. All I knew was about bowling like I did.

'The team, Duleep Mendis, Dav Whatmore, Arjuna Ranatunga, Aravinda de Silva, were great. There were tears in the hotel after, with them in the rooms, long nights. But it made the team stronger. We fought, got to the World Series final and then just a few months later won the World Cup. Against Australia.'

Muralitharan is a bowler of undeniable genius, a unique spinner who has taken a world record 527 Test wickets and who might even fulfil the prediction of his closest rival, Shane Warne, and go on to take 1,000. It is sad, therefore, that he should have to resort to a public relations exercise on British television.

Bowling in a singlet at the Nursery Ground at Lord's, he shows Mark Nicholas's TV crew how, with a steel and plaster elbow brace that Arnold Schwarzenegger could not straighten, he bowls with a bent arm of minimal flexion throughout.

There are some witnesses - including an English international umpire - who are very dubious about the legitimacy of Murali's action before the demonstration. But, as he bowls the off-break, top-spinner and the much-discussed 'doosra', there is no palpable difference in elbow-to-arm flexion with or without the brace from forearm to bicep.

What the exercise discloses, uncannily, is how much the dip, rotation and pivot of his shoulder, at the point of delivery, influences Murali's action. His shoulders flex more than yours or mine because of his elbows, and it is his shoulders that generate so much of his ball speed, rotating as they do on an axis greater than the norm. The human eye cannot take in all that.

The Laws of Cricket do not adequately make provision for such a quirky action. It is unlike any other in the history of the game.

To his credit, Murali appreciates the dilemma of cricket's administrators, even if he resents the impact they have had on his career. The ICC are custodians of the game - 'And I respect them for that,' he says. 'There are many people who genuinely want to help to find out the truth. But I know there are some - and they always get other people to say it for them - who think I am not an honest bowler. That makes me boil.

'I don't feel like a symbol, but I can feel that I am a bit of a test case. What they decide for me, will really set the standard for the game.'

After the experiment, Murali goes along to the ICC offices at Lord's for an informal chat with David Richardson. As the ICC general manager (cricket operations) explains: 'All suspect bowlers go before a bowling review group to establish whether an action up to that point is OK or not OK. You could go out the next day and be called again.'

Which is little consolation to a bowler who now has to operate under a cloud of suspicion until November when the results of the latest investigation into his action will be known. It makes his performances even more remarkable.

To understand Murali, it helps to abandon assumptions you might have about him. For a start, he betrays a surprising diffidence for someone so talented.

Just after he had come within a dropped catch of beating the record for the best innings haul in Tests, with nine for 51 against Zimbabwe in January 2002, I spoke to him for this newspaper and was astonished to hear how relieved he was not to have bettered Jim Laker's 10 for 53. 'They make you a target then,' he said, 'and I don't want that kind of pressure.'

As his ex-skipper Ranatunga says of Murali, 'He was young for a very long time.'

It was a different Muralitharan I spoke to last week, one who has matured into a gutsy fighter, a highly skilled adversary worthy of respect. 'Even if it's just for one day,' he says, 'Shane Warne wants to be the highest wicket-taker in the world. But he knows that I will always take the record back.'

There is a view in the game that he is not as mentally strong as Warne, who recently advised him to 'grow up' when he withdrew from the tour of Australia.

But Murali had reasons other than self-interest, as he explains. 'I didn't want the tour to be a media circus with me and Shane going head to head for the record, and if I can't bowl the doosra I don't expect Hayden, Ponting and Gilchrist to play with a thinner bat.'

The doosra - Urdu for 'the second one' - is, effectively, his wrong'un, the one that goes the other way, and it is at the nub of his troubles. He has been advised not to bowl it because the ICC consider it the most suspect. It is a view that puzzles Murali. 'My first reaction was, "Are they mad?" Then, "Why? What for? Why now? Because I'm close to the world record?" I was very very angry because I know these people who watch from television and far away don't know what they are seeing. Believe me, I know what a throw is. You can't throw and make the ball dip. I don't throw.'

After he had taken his 520th wicket, the Sri Lanka board told him to put away his mystery ball. John Howard, the cricket-loving Prime Minister of Australia, called him a chucker. Tensions grew on the eve of the tour. Murali's initial inclination was to defy them all. 'If I say no to the doosra now, does that mean it was something I should not have bowled for the past three years? It's not my main wicket-taking delivery anyway. I just bowl it once in a while to keep the batsman guessing.'

When Murali was first called by the Australians Emerson and Hair on the 1995-96 tour, he immediately subjected himself to rigorous biomechanical tests in laboratory conditions in Hong Kong and Perth to establish that there was no undue elbow straightening. He underwent further tests after Emerson called him there in 1999, then again this year before capturing Courtney Walsh's all-time Test wickets record against Zimbabwe, with 14 wickets in the two-match series.

The 'numbers' from the latest tests - using the most sophisticated motion-capture sensors available - went to the ICC and Sri Lankan authorities in April. The results will be released in November, so he will face South Africa in Sri Lanka next month without the doosra being available to him.

There is a wider dimension to the issue, and that is the integrity of all bowlers and, in a way, that of the game itself. Murali does not want special treatment, or the Laws adjusted to accommodate him. He wants justice. 'I will bowl within the law. I will do whatever the law allows. To change things just for me isn't fair on the other bowlers. But I still don't know what they want. You either call me, or you don't. But if you call me, you have to call a whole lot of others. I want to settle the issue.'

The Law had remained essentially unchanged since Victorian times until, in 2000, it was adjusted - largely because of the fuss over Murali's action. Law 24.2 reads: 'For a delivery to be fair in respect of the arm the ball must not be thrown' - that is, the arm must be as straight as humanly possible. Law 24.3 adds: 'Definition of fair delivery.... the elbow joint is not straightened partially or completely from that point until the ball has left the hand. This definition shall not debar a bowler from flexing or rotating the wrist in the delivery swing.'

Previously, there had been no mention of flexing. Two years ago, the ICC decided there should be degrees of tolerance in flexion: 10 degrees for fast bowlers, 7.5 degrees for medium pacers, and five degrees for slow bowlers. This made the false assumption that all bowlers have the same arm-speed.

Also, it did not allow for the difference in flexions when a fast bowler delivers a slower ball, a slow bowler a quicker ball, or the many nuances in between. All of these are virtually impossible for the umpire and match referee to measure during play. And sending suspect bowlers to be tested by biomechanics in laboratory conditions cannot recreate the stresses of a game, when a bowler tries to do that little bit extra to get a batsman out.

Complicating the matter further, what makes Murali different from every other bowler in cricket is his body. If you are born with arms that are bent, you are going to be unorthodox from the first ball you bowl. To get some idea of how unusual Muralitharan's elbows are in relation to his body, try this: stand up, push your elbows into your ribs, and turn your palms forward; your shoulders are distending a little, too.

Murali's elbow quirk has been assessed to be 32 degrees away from the norm for the right arm and 28 degrees for the left. His three brothers are similarly built, but none of them remotely approaches Murali in ability, confirming that his genius lies elsewhere.

He knew from an early age he had a special gift. 'It was just the way I did it naturally. I found I could turn it more than anyone else if I really used more than my fingers. I can turn a snooker ball on glass, too. I've tried it.'

Murali was still at school when he made his first-class debut and he was fast-tracked into the Test team when Australia toured in 1992. His first ball was to Allan Border. Murali's eyes sparkle as he recalls the experience.

'I beat his outside edge, once, twice, three times, whoosh, whoosh, whoosh! He turns round to Kaluwitharana [the wicket-keeper] and asks him what I'm bowling. Kalu says off-spin. Border hits the next one, but he's not confident. He asks Dean Jones the non-striker, what I'm doing, and he says leg-breaks.'

Murali has spread similar confusion ever since. The reason he is hard to read is he bowls off-spinners (as well as top-spinners and his doosra) with a wrist-spinner's action. He ran me through his repertoire.

'Ball in first two fingers, thumb to the side, the ball pushed out, that's the slider, the one that scoots low on landing. Same grip, only thumb on top and fingers running over the ball on release, that's the toppie. And the doosra - I really turn the wrist one more than normal.'

His action first caused a stir when England toured Sri Lanka in 1993. Dermot Reeve, who was in the squad but not the Test side, filmed Murali with a camcorder and that amateur videotape landed on the ICC's desks at Lord's shortly after.

Two years later, at a tournament in Sharjah, Darrell Hair was standing in a one-day tournament and aware that he would be officiating on Sri Lanka's tour of Australia that southern summer. He raised the issue of Murali's action with the ICC match referee, Raman Subba Row, who asked the television production company to show him replays.

At the end of the tournament Subba Row asked for tapes to be sent to Lord's for further inspection. How do I know this? Because I recorded, edited and delivered the tapes.

Murali might have shied away from his demons by pulling out of Sri Lanka's Australia tour, but he is far from finished.

'I will play for as long as I can,' he says, 'and bowl whatever they let me. I'll still take wickets.'