An unfortunate truth for cycling fans everywhere is that doping has had no small part to play in the history of the sport.

The use of performance enhancing substances were widely accepted in the early era of gruelling races like the Tour de France. A number of incidents however, including the death of Danish rider Knud Enemark Jensen at the 1960 Olympic Games team time trial, who was using amphetamines at the time, saw rules gradually introduced to combat doping.

Still, even to the present day, positive tests are not uncommon.

Lance Armstrong, who had won seven consecutive Tour de France titles until he was found guilty of using PEDs in a 2012 report, is potentially the most notorious drug cheat in cycling, if not sporting history.

But while cycling's uneasy relationship with doping continues, scientific gains have been made amongst the agencies trying to catch those who cheat, with the introduction of the Athlete Biological Passport (ABP) at the beginning of the 2008 race season by the UCI.

The World Anti-Doping Agency (WADA) is the ruling authority on anti-doping for more than 600 sports organisations around the world, including cycling's international body, the UCI.