THE email was sent from the Trump Tower in Manhattan at 16.57.21 local time on July 17, 2011. It read: “You are useless as a journalist.” The sender, Chuck Blazer, has made many mistakes in his career as a FIFA blazerati but this was a misjudgment on an epic scale.

Andrew Jennings, the recipient of the email, already knew the FBI was on the trail of Blazer, indeed the FIFA hierarchy. He knew that more than 30 years of work as an investigative reporter was about to yield the most spectacular result. The downfall of a corrupt regime at FIFA has gathered apace with Sepp Blatter, the president, now a victim of the relentless pursuit of indefatigable reporters. Blazer has been exposed and charged. Jack Warner, once the FIFA power in the Caribbean, has been banned from football for life. The governing body of world football teeters on the abyss. It would be absurd to say that Jennings was the only pursuer who took FIFA to the brink but he was certainly the leader of the pack.

‘’I wasn’t alone,” says Jennings. “I had colleagues in other countries, particularly in Switzerland and Brazil, and we shared information, we shared documents. We were committed to the story.” This is said with the irrepressible energy of an indefatigable 72-year-old. It has been a long march.

Jennings started his investigative work in the 1980s on corruption in the London police force and then scrutinised the Olympics. His obsession with chasing the truth was always with him. But what has fuelled an investigation into football governance that has run decades and caused Jennings to collapse in exhaustion, led him to bitter confrontation and invited ridicule upon him?

“Perhaps it is being born on the wet and windy coast of Scotland,” he says. “When you see what the fishermen can do, then you become humbled.”

However, as he left his birthplace of Fife some seven decades ago, the truth may be more prosaic. “I just think it is a great story and I am a reporter. It goes back to what your mother told you as a kid: ‘If you do bad things then you will get caught’. I want to show that is true.’’

He has worked on World in Action, on Panorama and his writing has appeared in several newspapers, notably the Sunday Herald. His victims have included Juan Antonio Samaranch, the International Olympic Committee president and now Blazer, Warner and Blatter who have all been forced from FIFA power and may yet be subject to the full force of the law. Other will inevitably be caught in net that Jennings has woven with care and patience.

In The Dirty Game: Uncovering the Scandal at FIFA, Jennings tells a tale of spectacular excess, limited transparency and missing tens of millions. The major scam was simple if extraordinarily lucrative. Votes on the venues for the World Cup final were sold. Tickets for the World Cup finals subsequently appeared on the black market after shady distribution contracts. Most of the money stayed at the top, some of it dripped down to the lowest ranked blazerati. “It was a typical organised crime structure,” says Jennings. The FBI seem to agree.

Jennings, who had laboured on the story since the late eighties, knew a successful resolution was in sight when he was contacted by the FBI in 2009. “That was very encouraging,” he says. “It was obviously great to have professional investigators on board. Incidentally, their interest was not piqued by the USA losing a bid to stage the finals. The timing shows that to be untrue.”

It was the FBI involvement that cornered Blazer who had siphoned $20m of FIFA revenue into private accounts and who could afford to conduct business and send ill-judged emails from Trump Tower. Blazer, 70, was a FIFA executive member from 1996 to 2013. He has admitted conspiring to accept bribes and his testimony may yet prove deeply injurious to Blatter who has been forced announce he will step down net year as FIFA president though remains clinging to the wreckage of a governing body. Blazer jousted with the “useless journalist” and lost. Blatter battled with Jennings and faces a similar fate.

Already seven of the governing body’s officials have been arrested and face extradition from Switzerland. Blatter, 79, has remained in Switzerland, with many suggesting he fears arrest if he travels to another country.

The story is now hurtling towards a sensational climax. Jerome Valcke, the FIFA general secretary, is suspended, Blatter’s bespoke jacket is on a particularly shaky peg and there is fear and trembling among many FIFA officials.

Jennings, alternately ridiculed and threatened could be forgiven for feeling a sense of vindication but he brushes that off. “No, not vindication and I was never disheartened. From Samaranch to Blatter, I have always known there was a story. The story was there. It just needed digging. I know it has taken some time but I knew it would unravel, certainly after the FBI became involved.”

He has faced up resolutely to the ridicule. He was routinely regarded as a “biased hatchet man” by FIFA and scorned as an obsessive nerd by many in the media.

“That did not worry me in the least,” he says. “I am a reporter and you expect to get abused and whispered about. I also expected some other reporters to be briefed about me and those briefings were hardly going to be complimentary. But so what? They are entitled to their say, even if it is objectionable and stupid.”

His language in The Dirty Game is robust, uncompromising. It reads like a sprawling, even unlikely thriller. The charges are, in contrast, laid with a delicate precision. “There is a lust for the story,” says the reporter. There is passion but there is also the hard work of sifting through emails, tallying figures and exchanging information with contacts and other journalists.

“It is why this can never be about personal vindication,” he says. ‘’We must always remember we are only reporters. Our job is to discover the documents, amass the evidence and get the sources.

That is hard work but I have not found it hard to keep going. Your heart lifts every other day as a new piece of evidence comes along. You think: ‘They have done that and they think they can get away with it. But they won’t’.’’

But what does he say when it is suggested that bribes and corruption are just the way of the world? “I give a robust reply,” he says. “This is a culture, a system that has cheated every fan. The sport has been cheated. Imagine all those millions that are pouring into football being used in a proper manner. You aim to stop corruption whenever and wherever it happens. This about gangsterism.”

He argues that one of the tragedies is that football also short-changed itself. “A properly run administrative body would have made more money from the game and distributed it so much better. That is the hope for the future,” he says.

And what about the 72-year-old? Has he any other target in his sights? “Believe me, there is much more to come on this FIFA story. As the Scots say, it will see me oot,” he says. The newspaper headlines continue to scream in agreement. The “useless journalist” may just be writing an obituary for FIFA.

The Dirty Game is published by Century at £12.99