Duncan Mackay
Jaimie Fuller head and shouldersWhen an athlete who has just served a suspension for doping returns to the sport and immeidately does it again, you know you've got problems. It's a situation that strikes at the very heart of credibility in world sport and when it becomes clear that punishment has failed to rehabilitate, we really are on a rocky road to somewhere worse than nowhere.

It was announced last week that Italian cyclist Danilo Di Luca had failed an out-of-competition drugs test and was immediately removed from the Giro d'Italia by his team.

This is a guy with history. Back in 2009, Di Luca was given a two-year ban following a positive test at the Giro d'Italia. He did get it reduced by nine months after agreeing to collaborate with the authorities and on April 26 this year, signed for the Italian team Fantini-Selle. Three days later, he was randomly tested and last week was confirmed as having failed the test. 

Fantini-Selle immediately sacked him and distanced themselves from his activities. The team will seek compensation from Di Luca under the terms of his contract for damages caused. The team manager has stated that they never wanted Di Luca in the team and only signed the rider due to pressure from one of the team sponsors.

So who's to blame? Well clearly the rider himself is right up there, but it appears that Di Luca was forced upon the team by a generous sponsor. It appears then, that this is all about money - and to hell with the consequences. Yeah, yeah, yeah, I know, it's a conclusion that doesn't exactly make me Sherlock Holmes but this is scary stuff because it reflects the true depth of a massive problem.

Danilo Di Luca in pink jerseyItalian cyclist Danilo Di Luca tested positive for banned drugs for a second time, only three days after signing for new team Fantini-Selle

Fantini-Selle say they were pretty much forced to take him by their main sponsor. You can imagine the scenario as the guy holding the purse strings demands "his man" is added and the team principal complies because he has no choice if he wants to keep his backer, his team and his job. There is no suggestion that the sponsors knew Di Luca was still doping but the point is that blind faith appears to have dug a deeper hole for the sport that they're all involved in.

Whatever might be said in hindsight about being sorry and making a mistake, it's time sponsors took on a greater level of corporate social responsibility when it comes to indulging the glamour world of professional sport. Should athletes who are offered redemption be subjected to rigorous testing by a governing body before they're handed their second chance?

Should sponsors insist - or be forced to confirm - they know their man is clean before allowing him (in this case) back on a bike again? For me the answers are obvious and there is one heck of a precedent that should serve as the ultimate case study.

Marco Pantani was a cyclist who excited the fans with his attacking style. He won the Giro and the Tour de France in the same year but he succumbed to performance-enhancing and recreational drugs. Although he never actually tested positive, the rumours were rife and he eventually went into a depression and died from acute cocaine poisoning.

Marco Pantani celebratingA deadly combination of performance-enhancing and recreational drugs evenutally killed another Italian cyclist, Marco Pantani

Throughout all this, the sponsor told Pantini's team that without Pantini there was no sponsorship. He continued riding to fulfil his obligations - and it killed him.

Thankfully, Di Luca (who's self styled nickname is the "Killer" by the way) didn't kill himself but the point is, sponsors are as much a part of this issue as the riders. The International Cycling Union (UCI) themselves are alleged to have been complicit in Lance Armstrong's doping activities and while not completely proven, the suggestion is they turned a blind eye because he was the star of the show and worth millions to them.

Danilo Di Luca is the latest example of a problem that is far deeper than just the athlete and his doctor. So until there's a plan that involves everyone and one that everyone signs up to, people will wonder if the athlete holding the trophy is truly legit. And for those who actually are, it's a complete disgrace.

If a sponsor turns a blind eye or chooses results over basic ethical standards, they too have blood on their hands.

Jaimie Fuller is the chairman of Skins and the founder of pressure group Change Cycling Now, whose members include Greg LeMond, Paul Kimmage and David Walsh. To follow him on Twitter click here.