In tears, and out of the Olympic Games: Italian walker Alex Schwazer admits using drugs

Schwazer said he had disguised the drugs inside a box of vitamins in a refrigerator

It was not the most likely sport to be rocked by the first doping scandal of the Olympics, but yesterday the man tipped to win gold in the race walk broke down in tears as he explained his expulsion from the competition.

Alex Schwazer, the Italian athlete who won the event in Beijing four years ago, revealed how he had hidden the banned substance in the home he was sharing with figure skater Carolina Kostner. "I made a huge error," he said. "And I can only repeat, I'm sorry."

At an emotional press conference in Bolzano, northern Italy, Schwazer said he had flown to Turkey in September with €1,500 (£1,200) to buy Erythro- poietin (EPO), a blood-boosting drug which increases the concentration of a red blood cells in the body and improves aerobic capacity and athletic performance.

He said he had disguised the drug inside a box of vitamins in a refrigerator at Kostner's home in Germany, where he was staying in July. Schwazer had been tipped to win a medal in the 50km event, which takes place in London on Saturday, but was expelled from the Games on Monday after testing positive.

The athlete – who admitted that his career was now over – said he had learnt how to use EPO over the internet and injected it daily in the bathroom to prevent his girlfriend Kostner and his parents from knowing what he was doing. "I did everything possible not to involve anyone else," he said.

Schwazer suggested he actually wanted to get caught because the guilt was psychologically devastating. He said he could have tried to skip the 30 July doping test, knowing he had made a final injection a day earlier, but did not. "I'm not made to take drugs or to deceive people, and I couldn't take it anymore. I couldn't wait for the whole thing to end," he said.

"When on the 30th the doorbell rang I knew it was the anti-doping people, I knew it was all over. It would have been enough to tell my Mum not to open the door or to tell them I wasn't home. But I couldn't take it anymore."

Even if he had not tested positive, he said he would not have gone to London. He added that he now hopes to lead "a normal life" away from athletics where he sees his girlfriend every night "instead of just twice a month".

He continued: "Carolina loves her sport. She skates because she likes it. I race walk because I'm good at it, but I don't like doing the same exact thing 35 hours a week, and sometimes at night when I'm shattered and thinking about getting up the next morning and doing it again, I get nauseous."

Schwazer said he felt pressured leading up to the Olympics by the "expectations that I had to dominate even more than before." But he added: "With doping, they say you get stronger, but for me, psychologically, it was the hardest."

He insisted that he kept Kostner in the dark about the doping until after his call from London on Monday to tell him he had tested positive. He said that since the doping news broke, she had remained supportive, "not leaving me alone for a moment".

He denied getting the EPO from Michele Ferrari, the Italian doctor banned by the Italian Cycling Federation who was a consultant to cycling champion Lance Armstrong.

Ferrari, who has also been banned for life by the US Anti-Doping Agency, said last week on his website he was not guilty of the charges. Schwazer said he consulted Ferrari "five or six times" but only for "technical advice" about training.