International Association of Athletics Federations president Sebastian Coe says he is deeply angered by the Russian doping operation that corrupted the London 2012 Olympics.
Last week an independent report revealed Russia "corrupted the London 2012 Games to an unprecedented degree".
Coe, who was chairman of the London 2012 Organising Committee, told Sky News: "I was angry (when I heard) because every athlete that was in that stadium had devoted half of their young lives to that moment.
"To have that dream, that ambition, that decade of hard work, the commitment of family and friends and massive financial sacrifice ripped asunder in such a shoddy way made me feel angry."
The revelation of the extent of Russian state-sponsored doping follows a re-testing programme that has taken the number of proven drug cheats who compete in London to 61, with the possibility of more to come.
Coe said he accepted Russia's actions had tainted the Games.
"Self-evidently it has in a way.
"The system was badly, badly infiltrated.
"It wasn't infiltrated in the testing system itself, it was the results management, the way those samples appeared, the system the athletes were in before they came to London.
"It makes me angry and it is depressing to see that when everybody worked so hard to make the Games what they were. They shouldn't be remembered for that but we have to accept that it was an unseemly chapter."
Athletics world governing body the IAAF, chaired by Coe, was the only world governing body to issue a blanket ban against Russian competitors for the Rio Olympics.
Asked if Russia would be re-admitted to world athletics before the World Championships in London next summer, he said it was too early to say.
"They will only come back in if we are absolutely satisfied that the systems they come from are safe and secure and give confidence to clean athletes."
He said he stood by the decision to ban them, which was criticised by some other sports at the time.
"Not sure vindication is the right word, it was not what we were looking for.
"We made a judgment that we felt the council felt unanimously that was in the best interests of the clean athletes.
"The charge sheet was mountainous. It wasn't going to resolve itself by thinking next year it might be better."
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