The U.S. Anti-Doping Agency (USADA) has informed Brock Lesnar of a potential policy violation, stemming from an out-of-competition sample collected on June 28, 2016, according to a statement released by UFC on Friday afternoon and reported on by ESPN and other news sources.

Lesnar successfully returned to the UFC against Mark Hunt 12 days later on July 9 at UFC 200. The results of the sampling were received by USADA on July 14.

UFC released the following statement on the matter via Twitter.

Statement by UFC on potential anti-doping violation by Brock Lesnar: pic.twitter.com/oydm46UzC5

— SportsCenter (@SportsCenter) July 15, 2016

Brock Lesnar has not performed for WWE since WrestleMania and is not scheduled to return until Sunday, Aug. 21.

Lesnar told the Associated Press late Friday night in a statement, "We will get to the bottom of this."