UFC 183: Anderson Silva, Nick Diaz Fail Drug Tests

The UFC announced that Anderson Silva and Nick Diaz failed their drug tests. The pair fought each other last weekend at UFC 183 at the MGM Grand Garden Arena. Silva (34-6) defeated Diaz in a unanimous decision, 50-45, 50-45 and 49-46.

Silva, a former UFC middleweight champion who is often regarded as the best fighter in history, was randomly tested out-of-competition by the Nevada State Athletic Commission on Jan. 9. The Jan. 9 test results, which came back after the fight, was positive for steroids, drostanolone and androstane, ESPN.com confirmed. He was also tested on Jan. 19 and 31. Those results have not come back yet.

UFC 183 was Silva's first fight after a 13-month break due to an injury. This is the first time in his career that Silva has tested positive for a banned substance.

"On Feb. 3, 2015, the UFC organization was notified by the NSAC that Anderson Silva tested positive for drostanolone metabolites on his Jan. 9 out of competition drug test," the UFC said in a statement. "UFC's understanding is that further testing will be conducted by the commission to confirm these preliminary results. Anderson Silva has been an amazing champion and a true ambassador of the sport of mixed martial arts and the UFC, in Brazil as well as around the world. UFC is disappointed to learn of these initial results."

NSAC chairman Francisco Aguilar added that Diaz also failed his drug test. Diaz, who was tested after the fight, tested positive for marijuana metabolites. The levels were above 150 ng/ML, which is the allowable limit. This is the third marijuana-related event for Diaz.

Both players could be fined as well as suspended. A full disciplinary hearing will be held for each player.

The commission will decide what to do with the results of the fight and will most likely rule it a no-contest.