King Mo's manager recalls non-anabolic steroid injection

"Both of us are very surprised by these results," Muhammed Lawal's manager Mike Kogan told USA TODAY. "Neither of us has ever heard of this drug. ... We honestly have no clue where this came from."

Other than food and drink, the only substances that Lawal takes on a regular basis are iron supplements, Kogan said. When Lawal had fluid drained from his knee a few weeks before the bout, he did receive an injection of a non-anabolic steroid, Kogan said.

At least four fighters have tested positive for drostanolone: former UFC lightweight contender Hermes Franca in July 2007; light-heavyweight Bill Mahood in October 2007; welterweight Dennis Hallman in November 2007; and former UFC heavyweight champion Josh Barnett in July 2009.