DENVER — Antonio Pettigrew gave up his Olympic gold medal Tuesday, two weeks after the sprinter admitted in court that he cheated to win at Sydney in 2000.

During last month’s trial involving former track coach Trevor Graham, Pettigrew came clean about using banned substances EPO and human growth hormone from 1997 to 2003. Graham, his one-time coach, was found guilty of lying to federal investigators about his relationship to a steroids dealer.

Pettigrew’s decision to give up the gold for the 1,600-meter relay was expected, and it came only a day after one of his teammates, Michael Johnson, also said he was giving back his relay medal in response to what Pettigrew had admitted.

“It takes courage to accept full responsibility for such egregious conduct, and hopefully, Mr. Pettigrew’s case will serve as another powerful reminder to young athletes of the importance of competing clean,” said Travis Tygart, chief executive officer of the U.S. Anti-Doping Agency, which handled Pettigrew’s case.

Pettigrew agreed to return the medal and all the other prizes he’d earned since 1997, including world championships in the 1,600 relays in 1997 and 1999.

The 40-year-old assistant track coach at North Carolina also accepted a two-year ban from track, though that point is largely symbolic given his age. He retired from track in 2002.

Johnson, writing in a column for Tuesday’s Daily Telegraph in London, said, “I feel cheated, betrayed and let down” by Pettigrew’s testimony.

It means that three of the four runners from the U.S. relay team in the 2000 Olympic finals have been tainted by drugs.

Twins Alvin and Calvin Harrison both were suspended for doping violations. Alvin Harrison accepted a four-year ban in 2004 after admitting he used performance-enhancers. Calvin Harrison tested positive for a banned stimulant in 2003 and was suspended for two years. Like Pettigrew, they were coached by Graham.

The Harrisons haven’t given up their medals, and Tygart said the Pettigrew case did not involve the brothers, or Angelo Taylor, who ran for the team in preliminaries.

“Each of those athletes might have to decide on their own,” Tygart said. “It seems like the right thing to do, as Michael Johnson decided.”

The U.S. Olympic Committee applauded the decision.

“After years of failing to acknowledge his mistakes and accept responsibility for his actions, Mr. Pettigrew is now stepping forward and doing so by returning the medal that was unfairly won at the 2000 Olympic Games,” USOC CEO Jim Scherr said. “We are pleased that he is now accepting responsibility and taking this step.”

During testimony in the Graham trial, Pettigrew said that once he started taking banned substances, he was able to run 400 meters in the 43-second range for the first time.

“I was running incredible times as I was preparing for track meets,” he said. “I was able to recover faster.”

The International Olympic Committee tried to strip the team of its gold medals after another teammate Jerome Young, who did not run in the finals, tested positive for doping and was banned for life from track. But a decision by the Court of Arbitration for Sport said the entire team should not be disqualified, and Pettigrew and the others were allowed to keep their medals.

Now, Pettigrew’s medal goes back, and so are all the other prizes and awards he won over the six-year span during which he admitted to using banned substances.