Alex Schwazer has insisted that he would be "happy" for his doping sample from the Beijing Olympic Games in 2008 to be retested.
The Italian walker, who won gold in the 50km in China four years ago, failed a drugs test ahead of the defence of his title in London earlier this week.
As a result, that has led some to question whether he secured the top prize in Beijing legally.
"I could only be happy for all my past doping samples to be retested and the results published," he told a press conference. "The last three weeks have been the most difficult of my life."
Schwazer has since announced his retirement from the sport.
