Adelaide - Lance Armstrong ended his international career at the Tour Down Under in controversial circumstances on Sunday, with continued allegations over illegal doping overshadowing his swansong.
The 39-year-old American refused to talk to reporters as he finished his last professional international race 65th overall, almost six minutes adrift of race winner Cameron Meyer of Australia.
Seven-times Tour de France champion Armstrong will now have to deal with a federal investigation in the U.S., triggered by former team mate Floyd Landis's allegations that he and other prominent figures in the sport used performance-enhancing drugs.
The Texan, who never tested positive throughout his career, has denied any wrongdoing, and said on Friday he was keen to cooperate with the U.S. Anti-Doping Agency (USADA) following fresh doping allegations published by Sports Illustrated.
Armstrong, a Team RadioShack rider, is set to make a few international appearances throughout the year, but will not be riding as a professional.
Team manager Johan Bruyneel, however, said Armstrong could ride a last pro race in the U.S. at the Tour of California in May.
"@tourdownunder is done. Thanks to everyone for coming out and supporting such a great race. #Adelaide, we're gonna miss ya," he wrote on Twitter after the sixth and final stage was won by Briton Ben Swift, who led a Team Sky one-two with New Zealand's Greg Henderson.
"I was struggling about halfway through the stage after my efforts on Willunga Hill yesterday, but my team did an absolutely perfect job for me," Swift told reporters.
"It was straight out of the book of how to do a lead-out, and all I had to do then was finish it off."
Garmin Cervelo rider Meyer held off Australian compatriot Matt Goss by just two seconds to win the race, with his nearest challenger eating into his overnight eight-second advantage, but unable to overhaul the leader.
Track specialist Meyer told reporters: "I can't thank my team mates enough. They were great. And credit to Matt Goss, too. He fought right to the end."