Medals won at the London Olympics should not be handed out until 2020 because it will be years before testers can be sure that the athletes did not take drugs, a leading sports scientist has suggested.
Samples taken from athletes at the London Games will be held for eight years at a new anti-doping laboratory in Harlow, Essex, allowing biochemists time to catch up with substances that are currently undetectable.
This policy of retrospective testing has operated with success before, most notably when the 2008 Olympic 1500m gold medallist Rashid Ramzi, of Bahrain, was stripped of his title in November 2009, a year after crossing the finish line at the Bird's Nest Stadium in Beijing.
Professor Chris Cooper, a biochemist at the University of Essex, also warned of a potential "perfect storm" of drugs development as cheating athletes exploit medical breakthroughs by pharmaceutical companies.
He said that blood doping, a form of cheating said to be popular with some Tour de France cyclists which involves artificially increasing the amount of red blood cells in the body, had attracted the interest of big pharmaceutical firms because it has implications for the treatment of leukaemia and cancer.
Erythropoietin (EPO) is the hormone that causes the body to produce more red blood cells, of particular interest to endurance athletes. The body produces it naturally under situations of "hypoxy" – when it is not getting enough oxygen, hence the effectiveness of high-altitude training.
Scientists have only recently developed tests to check for injections of artificial EPO, which is particularly difficult to monitor because the substance also occurs naturally in the body. "The big pharmaceuticals, they are interested in this pathway, in producing EPO. They may develop new compounds, new molecules, new methods of boosting red blood-cell count," Professor Cooper said.
"Sports don't have the money to develop these drugs themselves, they might cost £1bn, but the pharmaceutical companies do. These companies do talk to the anti-doping people, and rightly so, but new compounds could still find their way back into sport, long before any effective test for them could be developed. It's unlikely athletes will be taking drugs at the actual Olympics, anyone cheating will have done so long beforehand. But we might not find out for many years."
Professor Cooper, author of Run Swim, Throw, Cheat, is sceptical about the performance-enhancing effects of many banned drugs, most of which have their origins in the medical science related to treating illnesses.
"There is no evidence to suggest that something that gets a person from a sick level to a normal level will work to advance a person from a normal level to a super level," he said. "It works to make you normal, not super normal."
Lord Coe has consistently issued strict warnings in the build up to the Games, saying: "You come to London and you try to cheat, we will get you."
Blood samples will not only be tested against the 200 banned substances, but will also be examined for anything not previously encountered.
Olympic cheats: A history
1904: Thomas Hicks
The British-born US athlete won the 1904 marathon in St Louis, Missouri, but only after his coach gave him brandy and an injection of strychnine.
1968: Hans-Gunnar Liljenwall
The Swede was the first competitor to test positive for performance enhancing drugs. He lost his pentathlon bronze medal for alcohol use.
1986: Andreas Krieger
Shotputtter Heidi Krieger was one of many East German athletes doped with steroids. In 1997, Heidi went underwent sex reassignment surgery.
1988: Ben Johnson
Three days after breaking the world record in the 100 metres final in Seoul, the Candian sprinter tested postive for the anabolic steroid stanozolol.
2000: Marion Jones
The US sprinter and long jumper won three golds and two bronze in Sydney, but lost them all after she admitted she had taken steroids.