Brock Lesnar has been flagged by USADA.
The UFC released a statement Friday evening that Lesnar and the promotion had been notified by USADA of a potential Lesnar anti-doping violation. The potential violation comes from the failure of an out-of-competition drug test June 28, the release said.
The UFC said USADA received the testing results July 14 — five days after Lesnar defeated Mark Hunt at UFC 200 in his MMA return. The same was tested at UCLA Olympic Analytical Laboratory, a WADA-accredited lab.
USADA, as is its policy, did not release the name of the substance Lesnar tested positive for.
The UFC's anti-doping partner will conduct a full adjudication process before any sanction is levied.
Lesnar, the former UFC heavyweight champion and current WWE star, had not fought since 2011. The UFC waived the four-months notice an athlete is required to give before coming out of retirement to be placed in the USADA drug-testing pool, because Lesnar had been gone for so long.
Lesnar, 38, was tested by USADA six times in the four weeks before UFC 200.
In a media conference call before the Hunt fight, Lesnar was asked about allegations of performance-enhancing drugs.
"I'm a white boy and I'm jacked — deal with it," Lesnar said.
The UFC 200 main event had to be scrapped three days before the event because Jon Jones tested positive for banned substances in an out-of-competition test. Daniel Cormier fought Anderson Silva instead. Jones is also awaiting the USADA adjudication process.