India's former Commonwealth champion wrestler Narsingh Yadav has been given a four-year ban for doping and thrown out of the Olympics on the eve of his first bout in Rio.
The 27-year-old, who won the 74kg division at the 2010 Commonwealths and a bronze at last year's world championships, failed a test for an anabolic steroid in June but was cleared by the Indian authorities who accepted his explanation that a rival had sabotaged his food.
But the World Anti-Doping Agency appealed against this decision at the Court of Arbitration for Sport's ad hoc division in Rio and it agreed with WADA.
Narsingh, who also failed a test for the same substance 10 days later, will now be ineligible to compete until June 25, 2020, and must leave the athletes' village in Rio immediately.
It is the end of a contentious episode for Indian Olympic sport as Narsingh's selection was challenged in a Delhi court by the man he pipped for India's berth in the competition, double Olympic medallist Sushil Kumar, with Narsingh victorious on that occasion.
CAS, which is handling all the anti-doping cases at the Olympics, also announced sanctions for two athletes who tested positive earlier in the Games.
Brazilian cyclist Kleber Da Silva Ramos, who failed to finish in the men's road race, has accepted a provisional suspension after testing positive for the blood-boosting drug EPO and his case will now be handled by the International Cycling Union.
And Chinese swimmer Xinyi Chen, who finished fourth in the women's 100 metres butterfly, also accepted a provisional ban for a positive test for an illicit masking agent, which means the 18-year-old's result in Rio is cancelled and the case is referred to swimming's international federation.
Meanwhile, the International Olympic Committee announced the results of the vote for four new athletes' representatives to the Olympic movement's governing body.
German fencer Britta Heidemann, Korean table tennis player Seug-min Ryu, Hungarian swimmer Daniel Gyurta and Russia's pole vault star Yelena Isinbayeva won the most votes from the athletes in the Olympic village and will now serve eight-year terms.
Isinbayeva's election is the most eye-catching as she was a vocal critic of the decision to ban Russia's athletics team from the Rio Games for systemic doping, and was added to the list of candidates after the declaration cut-off.
IOC president Thomas Bach congratulated the quartet and said he looked forward to working with them closely to "further advance the Olympic movement".
"Athletes are at the heart of the Olympic Games and their voice is very important in the IOC," he added.