Dutee Chand, who won the right to compete in 2015 despite hyperandrogenism, has now tested positive for banned substances in an out of competition test.
The Indian sprinter was Initially banned in 2014 at age 18 due to hyperandrogenism but appealed to CAS. In 2015, CAS ruled in her favor and she has been free to compete since. In December, she tested positive for ostarine, andarine, and ligandrol.
First link is the recent doping positive; second is an article from 2015 when she won her right to compete.