It might have been at the opposite end of the stadium, but the second it happened, we knew. Thierry Henry had handled the ball before passing it to William Gallas, who duly scored the tap-in, thanks very much. In the 13th minute of extra time in a crucial World Cup qualification play-off against the Republic of Ireland, one of France’s greatest ever players had cheated in front of 80,000 people in the stadium and millions more at home. It was a cognisant breach of the rules, in plain sight and on the record. And I bring it up because of a conversation had just before kick-off.

We were in town for the football. But it being Paris and me being a cycling fan, the talk drifted to the Tour de France. Giovanni Trapattoni’s tactical nous is not exactly a fertile source of pub banter, after all. That summer Lance Armstrong had cheated his way through the last of his Tour de France abominations. There was no evidence revealed as of yet, no lifetime ban or farcical heart-to-heart with Oprah, but you didn’t have to be among the Texan’s closest friends to know that he’d been a drugs cheat all his career. Alberto Contador, meanwhile, went home in the yellow jersey. He looked cleaner than the American, but doubts remained.

The discussion centred around the fact that cycling was a sport for “junkies” — my colleague’s word, not mine — and that everything else wasn’t. Not exactly a nuanced argument, but top marks for directness. I maintained that cycling appeared dirty simply because it was the only sport actually trying to clean up its act up, but he stuck to a “show me the evidence” approach. For anyone interested in the cancer that is performance-enhancing drug use in professional sport, it’s a familiar one.

“I’ve never tested positive,” was Armstrong’s go-to defence. Show me the evidence.

Say what you like about him, but he’s clever. It’s not a denial of drug taking, simply a statement of the fact that he’d never been caught by a drugs test. A familiar note echoed through Henry’s comments after that night in Paris. “Yes, there was a hand,” he said: “But I’m not the referee.” Sure, I broke the rule— but I wasn’t caught.

Later that night, the continued junkie debate was a welcome distraction from the disappointment. And it’s one that I’ve been having on and off with people ever since.

Henry wasn’t the first or the last footballer to cheat on the pitch (and there is, perhaps, a moral distinction to be drawn between an opportunistic, instinctive breach such as Henry’s and a systematic, premeditated programme of doping), but because it was a somewhat personal experience it stuck with me. If a footballer is willing to do that in front of millions just to offer his side the slightest chance of victory, what would he be willing to do behind closed doors?

Every week there’s shirt pulling, fighting, violent tackles, diving, offside goals celebrated… all out in the open. Clear breaches of rules and flaunting of sporting principles. But doping? Hardly ever a whisper. Something’s not right with that.

I don’t mean to say that every single footballer on the planet is up to his gills in performance-enhancers every week, but it seems ridiculous that we’re supposed to believe that in such a bunch of chancers no one’s willing to use illegal substances that will give them an edge in what is the world’s most competitive and lucrative sporting environment.

To illustrate, Norway’s independent anti-doping database dopinglist.com currently has 24 provisional suspensions and nine disqualifications on record from last summer’s Olympics. There were 14 cases in track and field alone, out of 2,231 athletes.

In contrast, Fifa says that it tested 28,587 blood or urine samples in 2011. Of these, just 19 tested positive — five of which were from the North Korean women’s team. There are clear similarities to cycling’s approach to the problem in the 1990s when only the workaday, insignificant among the peloton were ever found to be guilty of infringements.

The Professional Footballers’ Association has 4,000 members in England and Wales and the last high-profile doping case there was when the Portuguese full-back Abel Xavier was banned for 18 months in 2005 while playing for Middlesbrough — for taking anabolic steroids. That’s eight years without a high-profile bust.

The more dope-fluent among you might have scoffed at Xavier’s choice of poison. Steroids, after all, are so passé.

Sure, they can be handy occasionally, if you’ve got a solid alibi. Armstrong kept a chummy doctor nearby who was always good for a back-dated prescription. But it’s easy to trace and there is a plethora of performance-enhancing drugs out there which are more difficult to test for.

Take GW501516 for example, a drug so trendy it doesn’t even have a proper name yet. It’s a receptor agonist that stimulates enzyme production similar to those produced when exercising and was developed with the aim of treating obesity. When combined with proteins like Acadesine, used to treat leukaemia, it also greatly increases aerobic endurance — and causes cancer. An article in the New Scientist earlier this year warned that the product originally developed by GlaxoSmithKline “rapidly causes cancers in a multitude of organs, including the liver, bladder, stomach, skin, thyroid, tongue, testes, ovaries and womb.” Nothing’s perfect, right?

Despite the dangers, GW501516 made its way onto the black market and is now making headlines. The Russian track cyclist Valery Kaykov has been banned already and there are unconfirmed reports that more bans in other disciplines are to follow. Impressively, for fans of acts of unbridled stupidity at least, Kaykov’s positive test came just weeks after the World Anti-Doping Agency (Wada) actually warned potential cheats that the drug was one of the more dangerous illegal options available to them.

In a bid to protect these athletes from their own ignorance, Wada took the unusual step of releasing an official warning, as they put it: “to ensure that there is complete awareness of the possible health risks to athletes who succumb to the temptation of using GW501516 for performance enhancement.”

Not everything is so risky, of course. A footballer could partake in a simple bronchodilator like Clenbuterol to improve his lung capacity and then, having spoken to Spain’s Contador, found out the most convincing way to blame the drug’s appearance in a urine sample on contaminated food.

Or they could blood dope with transfusions, whereby several units of blood are withdrawn when the body is in optimum condition — preferably while training at altitude, say for instance, at one of those popular summer training camps held away from prying eyes—and re-injected when the athlete needs a boost.

Then there’s Erythropoietin. EPO is a naturally-occurring hormone produced by the kidney that controls red blood cell production. The doper’s dope, the synthetic version increases red blood cell levels in the body, thereby increasing the body’s aerobic threshold. Basically, the hormone travels around in your system until it comes into contact with special receptors in the bone marrow where it starts a chain reaction that creates many more red cells. The EPO-receptors in these new cells are replaced by new receptors which are attracted to iron-transporting proteins. Elsewhere, globin proteins combine with haem molecules — they contain iron — to make haemoglobin, which collects oxygen in the lungs and is then carried by the iron-loving red blood cells to the body’s muscle tissue — fuelling the fire, so to speak.

In athletes, the synthetic EPO allows them to perform at peak level for much longer because the improved supply of oxygen to the muscles delays lactic acid build-up.  This is especially useful in a sport in which repeated changes in tempo and bursts of pace without the hassle of recovery time might be useful. Like cycling... or football.

The downside of it is that super-rich blood becomes a dark red gel and when the body’s not running at full tilt there’s a significant danger of a horrible death. Anecdotes abound of cyclists spending the night in their hotel rooms on training machines to keep the blood flowing — after riding for hundreds of kilometres during the day. The upside is that it’s almost completely untraceable.

In recent years, some sports have spent a great deal of money trying to eradicate EPO usage. The biological passport, an electronic record of indicative biological markers in an athlete’s system that can be observed to detect spikes and irregularities with much greater precision than standard urine testing, is proving useful.

Obviously, it’s not yet been adopted by football. In fact, almost no modern doping tactics have been embraced, even if Fifa is in the process of playing catch-up. According to Wada’s president, John Fahey, “team sports players can go their entire career without being tested once.” Not exactly confidence-inspiring.

In a recent statement, the sport’s governing body said, “Fifa is developing plans to introduce this new tool, including a steroid profile through urine and a blood profile, for the … 2014 World Cup in Brazil, where in and out-of-competition tests would be conducted on all participating players.”

This sounds promising from a football perspective, but as fans of other sports will tell you, it still leaves a lot of questions. Questions like when, where, how and who?

If most athletes can avoid testing or at least be warned well in advance, then what’s the point? There’s a crucial ‘glow-time’, the period when a performance-enhancing drug (PED) will show up on tests and once you can predict the tester’s movements it’s easy to hide. Then there’s the ‘hematocrit holiday’, whereby an athlete in the know is left out of a squad if his doctors are afraid of his red blood cell levels arousing suspicion. Which makes you wonder if some managers might be ‘resting’ players for other reasons than recuperation.

Any efforts to stem the use of PEDs should be applauded, but the problem with Fifa’s first serious steps towards facing up to the problem is that while they’re inexperienced in the field, the people they’re up against are seasoned pros.

As the Operación Puerto probe in Spain proved, doping cross-pollinates. The man at the centre of the scandal, Eufemiano Fuentes, has repeatedly insisted that while he was stung by cycling investigators, he was never exclusively used by cyclists. It was hoped that the investigation would name and shame several high-profile athletes, tennis stars and footballers, but though investigators currently have 216 blood bags in their possession, Judge Julia Patricia Santamaría ruled that revealing the owners would be a breach of doctor-patient confidentiality. The Italian National Olympic Committee, Wada and the International Cycling Union are just three of the groups who disagree. They’ve appealed against the decision and Fuentes has already said he’ll name all the owners. It promises to be an interesting list and one that almost certainly includes several high-profile footballers.  

Another interesting list would be the number of “therapeutic usage exemption” issued across all professional sports every year. A TUE justifies the use of banned substances for medical reasons, but they’re commonly used as nothing more than a bureaucratic way to excuse doping. A skin cream for a rash, for example, can contain steroids and produce similar signals to illegal PEDs in tests. So a simple note from the club doctor would make a serious problem go away.

The Premier League’s testing is handled by the FA, which says that it not only adheres to Wada guidelines, but actually exceeds them. Wada disagrees. You decide who to believe, but the records show that the only players to do be caught doing anything wrong in the last two years have been Barnet’s Mark Marshall and Sunderland’s Lewis Gibbons, who tested positive for cocaine use rather than a PED.

On the continent, it’s much the same. The former president of Real Sociedad, Iñaki Badiola, has admitted that the club ran a systematic doping campaign between 2001-07 and has hinted at a connection to Dr Fuentes. Sociedad’s president at the time was José Luis Astiazarán, the current president of the Liga de Fútbol Profesional.

The doctor himself maintains that Real Madrid have an unpaid bill to settle with him, unrelated to doping but surely indicative of a close relationship, and a trusting one too because the Spanish club called the doctor as a witness against the French newspaper, Le Monde. But despite this, the last case dopinglist.com has on file for Spain dates from 2002, when the Athletic midfielder Carlos Gurpegi was suspended for steroid use.

In Italy, the investigating magistrate Raffaele Guariniello pursued Juventus for much of the 2000s over evidence he’d collected that suggested there was a PED system in place in Turin, but little came of it. The trial lasted five years and it proved that Juve and other Serie A sides had used illegal substances in the 1990s. It also found that a Turin-based doctor had almost certainly supplied EPO to a host of bianconeri players but the club escaped punishment because the court couldn’t prove that it had ordered the usage. Video evidence was discovered of Fabio Cannavaro injecting himself while playing for Parma, although he claimed it was vitamins.

The first judge found the club not guilty, the state appealed and in 2007 a revised verdict found Juventus guilty of sporting fraud — after the statute of limitations had expired.

Everyone got away with it. The only person to be caught since is Sassuolo’s Leonardo Pavoletti, who failed a drugs test before a Serie B game last year. Calciopoli, the match-fixing scandal that hit Italian football in 2006, seemed to suggest that Serie A’s problems lay elsewhere and little has been done since to tackle the problem of doping.

The system Fifa plans to implement will be a welcome addition to anti-doping measures, but it will mean little to the sport overall if more is not done domestically. Part of the reason that the biological passport system has been so successful in athletics, cycling and other sports is that athletes are now tested all the time, wherever they are in the world.

There are fewer and fewer opportunities to cover up the glow-time and as the punishments become more severe and the odds of being caught shorten, few young athletes are willing to start off on that slippery doping slope.

If any dopers heading to the World Cup only have to worry about being caught in Brazil, they’ll simply tailor their PED regime to ensure that their tracks are covered and the work that Fifa does hand-in-hand with Wada will be for naught.

In 2014, Fifa plans to conduct in and out-of-competition tests on all participating players. It’s a commendable goal, but as Lance Armstrong never tired of saying, he spent his whole career without testing positive. He was protected by his teammates, managers, national coaches, doctors and a network of political allies within professional cycling. Fifa must make sure that no such Machiavellian systems exist within football if they’re going to succeed.

At least one high-profile figure within the game doesn’t seem convinced that Fifa’s anti-doping dealings will be completely transparent. Speaking recently about the measures, the Arsenal manager Arsène Wenger openly doubted the system’s effectiveness. “It is very difficult for me to believe that at a World Cup,” he said, “where you have 740 players, you come out with zero problems. Yet mathematically that is what happens every time.”

Wada’s president John Fahey is more optimistic but added an important caveat to his praise of Fifa after meeting with Sepp Blatter to discuss the matter. “We are very interested in continuing the work on biological profiles,” said Fahey in the Fifa statement. “Wada is very satisfied with the commitment of Fifa on the biological profiles. There is always more which can be done in the fight against doping, but we know Fifa has always been serious in this domain, [but] we think the domestic leagues can complement what Fifa is already doing.”

That’s an understatement. Perhaps part of the reason that little has been done openly to confront the possibility of doping in football is that the stakes are a lot higher than they are in other sports. At the Olympics, the athletes compete as individuals. Fans will celebrate success happily enough, but there’s no commitment to sharing the burden of a heavy loss or the blame for a scandal. Pro cycling’s teams exist at most for a few years and are then replaced by new sponsors and new riders. There’s never the generational, socio-geographic connection that exists between football teams and their fans and the world’s biggest cycling events continue regardless of who rolls up to the start line. 

Football, in contrast, is fuelled by emotional and historical bonds between the clubs and the fans and political and financial bonds between the clubs and the leagues. La Liga would mean little without Barcelona or Real Madrid, after all, and the Premier League’s importance would dwindle should a club like Manchester United or Liverpool cease to exist.

The betting scandals that have rocked Italian football over the last decade provide a glimpse of the dangers. Serie A’s decline in recent years has been unquestionably exacerbated and complicated by Juventus’ legal problems and subsequent relegation, as the league became less competitive at home and less influential abroad without the Old Lady’s muscle.

There’s a lot on the table. A few key figures could bring the whole house of cards down — and the powers that be are aware of this and understandably hesitant to test fate. Taking Fahey’s advice to “complement” Fifa’s commitment could bring disastrous consequences, but ignoring the problem threatens a future far more ruinous.

The clubs could start by explaining their dealings with people like Fuentes. Or they could be more open to the idea of allowing greater testing freedom to impartial organisations like Wada. They certainly need to at least join the conversation and admit that, as Wenger suggested, it does seem a little odd that there are no problems in football.

There’s doping in athletics. There’s doping in golf. Cycling was riddled with it. There are six doping cases registered on dopinglist.com from billiard sports and eight related to roller skating. It’s a universal problem, one that grows exponentially with money and fame. And there are none more rich or famous than footballers.