Siver's "A" sample was deemed inconclusive two weeks ago and led to his "B" sample getting tested. In turn, the results were a positive flag for human chorionic gonadotropin (HCG), a female fertility drug. While that may seem odd at face value, HCG is commonly taken to combat low testosterone following steroid use. Manny Ramirez famously tested positive for HCG while with the Los Angeles Dodgers, which led to a 50-game suspension.
At this time, the Nevada Attorney General's office is preparing its complaint against Siver.
This is the first time Siver has failed a post-fight drug test. As such, he will likely receive the standard nine-month suspension and a fine. In addition, his UFC 168 decision victory over Manny Gamburyan will likely be overturned to a no-contest.
Also, in addition to the news that Siver had failed his drug test, fellow UFC 168 fighter Siyar Bahadurzada officially passed his drug test. Bahadurzada's "A" sample, like Siver's, was deemed inconclusive. However, his "B" sample came back clean.
Siver is currently ranked as the No. 8 featherweight in the UFC, and he owns a 3-1 record in the division. His win over Gamburyan followed a third-round knockout loss to Cub Swanson, who he fought at UFC 162. He is yet to comment on either the initial "A" sample coming back inconclusive or the official "B" test failure.
Stick with Bleacher Report for more details as they become available, and watch for the Nevada State Athletic Commission to begin the hearing process in the coming days.