"The CAS Panel found it more likely than not that the origin of the prohibited substance was contaminated beef consumed in a restaurant the day before the test," sport's highest court said in a statement.
Russian swimming chief Vladimir Salnikov said on Tuesday the atmosphere surrounding his team at the Olympics reminded him of the Cold War, and criticised American breaststroke champion Lilly King for attacking the integrity of her Russian rival.
Tainted wrestler Narsingh Yadav was exonerated of doping charges by the National Anti-Doping Agency panel, probing the positive tests on his urine samples on Monday. It ruled "there is no negligence on the athlete's part and he is a victim of sabotage".
Too much exercise and eating disorders are some of the underlying factors that may affect fertility in women, says gynaecologist Dr Archana Dhawan Bajaj,
Summary of sports events and persons who made news on Wednesday
Having sex every other day may be optimum, says Dr Raghuveer Karne. Prolonged abstinence can increase the number of dead sperm.
Sun Yang became the first Chinese swimmer to win the Olympic men's 200 metres freestyle gold medal on Monday.
The suspense over wrestler Narsingh Yadav's participation in the Rio Olympic Games was prolonged further after the National Anti-Doping Agency deferred its final verdict on the doping scandal to Monday.
Sports Minister Vijay Goel has hinted that Narsingh Yadav's prospects of participating in the Rio Olympics is virtually over, but said the wrestler will be given a fair chance to defend himself.
A summary of sports events and sports persons, who made news on Tuesday
Following badminton World No 1 Lee Chong Wei's provisional ban, Rediff.com brings you ten top sports persons who gave in to drugs - one of the mighty perils that has affected modern sporting culture.
A summary of sports events and persons who made news on Thursday
Summary of sports events and persons who made news on Wednesday
A summary of sports events and sports persons, who made news on Saturday
Hosts Brazil won their first gold of the Rio 2016 Summer Games after Rafaela Silva won the women's-57kg judo event on Monday. Another country to open their 'gold account' was Croatia, thanks to trap shooter Josip Glasnovic's superb effort in the shoot-out.
Summary of sports events and persons who made news on Wednesday
Narsingh Yadav's chances of making it to the Olympics will be known on Thursday. The National Anti-Doping Agency's disciplinary panel adjourned its hearing on the dope scandal surrounding the wrestler on Wednesday evening, even as he failed a second dope test and lodged a police complaint against two fellow-grapplers.
UEFA president Michel Platini hit out at FIFA chief Sepp Blatter on Friday, saying the Swiss has stopped serving the cause of football.