Clean or not, Contador's presence in the Tour will not be an embarrassment

British hopeful Bradley Wiggins, who recently won the Critérium du Dauphiné and in doing so proved himself back to the form he displayed when he came fourth in the 2009 Tour de France, has said that "it is not a good thing [for cycling] that a bloke who tested positive four times is in the race" in reference to Alberto Contador who tested positive for the banned bronchodilator Clenbuterol during last year's Tour.

Contador, like any professional cyclist at the top of his game, is no stranger to the murky world of doping. In 2006 he became caught up in the notorious Operation Puerto which followed Jesus Manzano's exposure of widespread doping in his team and the shady practices of Doctor Eufemiano Fuentes, but was subsequently cleared of all charges by the Spanish courts and by the UCI. He was questioned again in connection with the case in December and rather inadvisably refused to submit to a DNA sample which would have either proved or disproved links to nearly a hundred bags of blood plasma - each with a cheeky shot of EPO for an added kick - that had been recovered by police during their investigation. In doing so, he probably did his career more harm than a conviction would have done - had he have been linked to it, he'd have received a suspension and once it had passed he could have returned to the sport. By refusing, he ensured that there was always going to be a great big question mark hanging over him. However, anyone who has ever found themselves the target of false charges will be well aware that once you're cleared you want to move on and continue with your life - Contador may regret refusing the DNA test now, but at the time he must have been heartily sick of the entire case and hoped to hear the last of it.

Contador is almost unique among climbers in that he can also perform at a very high level in time trials, a factor that has contributed to his success.

That question mark haunted him in the 2009 Tour when, following a spectacular climb up Verbier - the fastest in Tour history - in Stage 15, Greg LeMond wrote in a column for the Le Monde newspaper that Contador would have needed an oxygen transport rate in excess of that achieved "by any athlete in any sport" and demanded that he proved he was capable of such a feat "without falling back to the use of performance-enhancing products" and likened his victory to that of "a Mercedes sedan winning on a Formula 1 circuit." During a press conference the next day, Contador once again unwisely decided to side-step the issue, increasing suspicions further. LeMond had based his accusation on figures calculated by Antoine Vayer, the trainer of the rival Festina team, which were called into doubt by physiologists including the highly-respected Andrew Coggan. Vayer assumed that Contador would have needed to maintain an average power output of 490 watts which, in a man weighing 83kg, would equate to 99.5ml per hour per kg - which would be unusually high. Coggan criticised Vayer's calculations which he termed sloppy and noted several areas which could contribute to false results, such as failing to take in decreased air resistance at altitude. Furthermore, virtually all the top riders had climbed Verbier in record times that day - including Andy Schleck and Lance Armstrong, neither of whom have ever been proven to be involved in doping despite countless accusations and investigations in the case of Armstrong - suggesting that conditions on the mountain were simply conducive to high-speed cycling. He also noted an inconsistency between Vayer's given length of the climb, 8.6km, and the official length as given by the Tour de France organisers, 8.8km, more than sufficient to skew the results. Coggan concluded that the rider's average power would in fact have been more like 450 watts, equating to an oxygen transport rate of 80ml per hour per kg which could be expected for a man of his build and level of fitness.

As we all know, Contador gave a urine sample in September 2010 which tested positive for a drug called Clenbuterol, a sympathomimetic steroid and bronchodilator prescribed to asthmatics to ease breathing - thus enabling more oxygen to be absorbed into the blood - and the cycling press leapt on the case like starving wolves, in some cases predicting the end of his career. Once again, it was only a matter of time before doubts arose - what had at first seemed to be a case of an athlete being caught red-handed in the act of cheating turned out be rather more complicated. First of all, Contador failed one test only - his sample was declared clear in other tests to which it was subjected. Various people involved in cycling went on record stating that Clenbuterol is of little use as a performance-enhancer, especially in the miniscule amounts suggested by Contador's sample which were 40 times lower than would be required for any noticeable effect and Dr. Douwe van Boer (Contador's scientific advisor) claimed that it would have to be administered in amounts 180 times that discovered in the sample to have any chance of giving the recipient a competitive edge, supporting Contador's explanation that he had not deliberately taken the drug and that it had entered his system via contaminated food, most likely beef - it was used by veterinary surgeons to relax the uterus in cows and can be used illegally to promote the growth of lean meat in livestock destined to become food, which appears to add some credence, as does the support for the explanation given by Dr. Don Catlin, a highly-respected scientist and one of the driving forces behind modern anti-doping measures.

If he can repeat his 2008 Vuelta
success, Contador will be the
only cyclist to have won all
three Grand Tours in a single
season.

The incident led to the Spanish Cycling Federation proposing a one year ban for the cyclist but, following an appeal, all charges were subsequently dropped in early 2011 and he returned to professional racing in February. The independent World Anti-Doping Agency and UCI both appealed the Spanish decision to the Court for Arbitration in Sport in March and a hearing was scheduled for June but later put back after Contador's lawyers requested more time to prepare. It is now scheduled for early August later this year, until which time Contador is legally free to ride in professional events. If that's the case, there should be no reason that he should be singled out for a crime that in view of his current cleared status he should be considered not to have committed and banned from taking part in this year's Tour de France - during which he will doubtless be subjected to a barrage of tests and will, if he cheats, be found out. Bearing that in mind, the decision to enter the race if he is/has been doping would seem extraordinarily stupid because a positive test will ruin his chances with the Court.

The UCI supports this view, stating that until the Court finds him guilty, should it do so, Contador "has the right to be treated like every other rider who takes part in the Tour de France." Reporting on the case, Republican American says that his participation in the race could do great damage to the sport and compares it to Lance Armstrong's return from retirement in 2009. However, the opposite is more likely to be the case - if Contador consistently produces clean samples this year, his status as one of cycling's true heroes and an all-time great will be cemented and will pave the way for him to attempt victory in the Vuelta a Espana, which would make him the only cyclist ever to have won all three Grand Tours in a single season and which would generate enormous publicity for the sport. If he cheats and is found out - and there's little doubt he would be - then professional cycling can be shown to have got its act together following the scandals of a few years ago and the sport's reputation cane be repaired once the world is aware that those who obtain an unfair advantage by using performance-enhancing drugs will be caught and will be stripped of their titles.

"It is also bad for those teams that are fighting to be clean, as is the case with my team, Sky," says Wiggins, who has become Britain's best-ever hope of a Tour winner. If that's the case, he should welcome Contador's chance to prove that he too is clean, because if an athlete can perform in the way he does without resorting to drugs then that's one of the strongest arguments against doping anyone could ever want.