Lance Armstrong tweets that he's returned Olympic bronze medal

Disgraced cyclist Lance Armstrong tweeted Thursday that he's handed over the bronze medal he won at the 2000 Summer Games, adding that it should be at International Olympic Committee headquarters in Switzerland "asap."

Earlier this year, the committee stripped Armstrong of the medal he won in Sydney and asked him to return it.

Armstrong -- after years of heated denials -- in January admitted to doping throughout his storied career, which included seven Tour de France wins.

Armstrong's tweet Thursday included a photo of the medal and said "the 2000 bronze is back in possession" of U.S. Olympic officials.

Mark Higgins, a key member of Armstrong's camp, did not elaborate on how or why the medal was turned over, beyond saying it was given to the U.S. Olympic Committee.

The Texas-born athlete was a rising star when he was diagnosed in 1996 with testicular cancer at the age of 25.

After getting treatment, he returned better than ever -- reeling off his consecutive string of Tour de France victories between 1999 and 2005. Armstrong left the sport after his last win, only to come back four years later and place third in cycling's most prestigious race.

His historic rise came at a time when cycling, generally, was mired in repeated doping scandals. Armstrong himself was not immune to such accusations, but each time he fired back at his critics and vehemently insisted he'd been clean.

Yet the tide began to turn against Armstrong in June 2012, when the U.S. Anti-Doping Agency said it had opened proceedings against him and five of his former teammates. The agency, which is designated by Congress as the country's official anti-doping organization for Olympic sports, announced two months later that it was stripping Armstrong of his Tour de France titles and barring him from future competitions for life.

Armstrong remained defiant until sitting down with Oprah Winfrey last January. Calling himself "deeply flawed," Armstrong admitted that he'd used an array of performance enhancing drugs and took blood transfusions to excel in the highly competitive, scandal-ridden world of professional cycling.

Armstrong admits using performance enhancing drugs

"This is too late, it's too late for probably most people. And that's my fault," he said. "(This was) one big lie, that I repeated a lot of times."

The IOC asked for Armstrong's Olympic medal back the same day the first part of the Winfrey interview aired.