Australian cyclist Michael Rogers will face no further action over a positive test for clenbuterol he delivered at a race in Japan last October.
The 34-year-old former Team Sky rider, now with Alberto Contador's Tinkoff-Saxo squad, was provisionally suspended after testing positive for the steroid.
But the International Cycling Union said in a statement on Wednesday it accepted that he ingested the substance via contaminated meat at the preceding Tour of Beijing.
"Upon careful analysis of Mr Rogers' explanations and the accompanying technical reports the UCI found that that there was a significant probability that the presence of clenbuterol may have resulted from the consumption of contaminated meat from China - where he had taken part in a race before travelling to Japan," a UCI statement said.
"As a result, the UCI has proceeded with the automatic disqualification of Mr Rogers' results at the 2013 Japan Cup Cycle Road Race (the competition during which the positive sample was taken) but, after consulting WADA, decided that he should not be sanctioned any further."
Rogers issued a statement of his own following the UCI's announcement, expressing his relief.
"Over the past four months, my family and I have endured a very difficult time," he said.
"The UCI's decision means I can return to racing immediately, and I am looking forward to getting back to work, competing in the sport I love.
"I wish to take this opportunity to thank my family, friends, team-mates, colleagues, medical experts and fans who have showed continued support and understanding.
"Further, I wish to show my gratitude to the board of Tinkoff-Saxo for the professional manner with which this ambiguous ordeal has been handled.
"Thank you for having the perception of what is right, rather than following the path of least resistance."
Although clenbuterol is banned in China, there have been previous cases of contamination due to its continued use in agriculture.
WADA issued a warning to athletes in 2011, telling them to only eat in approved restaurants and cafeterias when competing in China and Mexico due to contamination cases in those countries.
In the lead-up to the 2012 Olympics, Chinese Olympic rower Huang Wenyi used her blog to reveal that Chinese athletes had been banned from eating pork due to fears over the meat.
Wednesday's UCI statement added: "The UCI is monitoring very carefully the latest developments concerning clenbuterol, and will continue to take appropriate steps to ensure riders are properly informed.
"However, the UCI reiterates that the presence of clenbuterol in a urine sample constitutes an anti-doping rule violation under the World Anti-Doping Code and the UCI anti-doping rules. It is generally acknowledged that in certain countries a risk of meat contaminated by clenbuterol can exist and produce, in specific conditions, a positive sample from an athlete.
"WADA has issued specific warnings about this problem in China and Mexico. Consequently, the UCI reiterates its recommendations to the athletes and teams concerned to avoid eating meat in these countries."
Rogers' team-mate Contador tested positive for clenbuterol in July 2010.
His explanation that he had eaten contaminated meat was initially accepted but he was later banned for two years by the Court of Arbitration for Sport, and stripped of his 2010 Tour de France win. Contador made his return to the Tour last summer with Rogers as his chief lieutenant on the road.
In the 2012 Tour, Rogers rode for Team Sky and served as a key tactician as Sir Bradley Wiggins took the victory before joining Tinkoff-Saxo prior to the start of the 2013 season.