(CNN) -- Sebastian Coe admits the positive drugs test for Beijing Olympic 1,500 meter champion Rashid Ramzi has tarnished the reputation of the event that will always be associated with his name.
Lord Coe has expressed his 'abhorrence' at Rashid Ramzi's positive drugs test.
Ramzi, who is from Morocco but runs for Bahrain, is one of six athletes from Beijing who were revealed this week to have been caught out by new tests for the blood-boosting agent CERA, a form of EPO.
But Lord Coe, chairman of the London 2012 Olympics and an executive board member of the IAAF, international athletics' ruling body, insists the war against drugs in sport is being won and warned that London would have best possible testing program.
Coe, the 1,500m Olympic champion in 1980 and 1984, told PA Sport: "It's abhorrent whenever there is a positive test but I think anyone who ran at our distance will find this a pretty disfiguring moment.
"But we have caught him out, that's the important thing. There is some cause for optimism because -- and this is no idle threat -- we are now much smarter, about how to catch these people.
"And for those athletes we have our suspicions about the message is very clear: we will get you."
Coe accepted an Olympics in London without drug cheats looks impossible but added: "We are winning the battle, the technology is much better, and we will present the best-possible environment for a drug-free Games in London."