Australian cyclist Stuart O'Grady has admitted using the banned substance EPO 15 years ago

The Australian announced his retirement from the sport earlier this week after helping Orica-GreenEDGE to victory in this year's team time trial on stage four.

The 1998 Tour gained notoreity when the Festina team were kicked off the race after a medical team member was arrested at the French border and customs officers seized banned substances, including EPO.

O'Grady, 39, who also wore the yellow jersey, told the Adelaide Advertiser: "The hardest part of all this is I did it for two weeks before the Tour de France.

"I used extremely cautious amounts because I had heard a lot of horror stories and did the absolute minimum of what I hoped would get me through.

"When the Festina Affair happened, I smashed it, got rid of it and that was the last I ever touched it.

"That is the hardest thing to swallow out of all this. It was such a long time ago and one very bad judgement is going to taint a lot of things and people will have a lot of questions.

"Leading into the Tour I made a decision. I sourced it [EPO] myself, there was no one else involved and didn't involve the team in any way. I just had to drive over the border and buy it at any pharmacy."

O'Grady, a former track cyclist, won medals at three Olympics, including gold in Athens in 2004.