It is the second time Lesnar has failed a drug test after it emerged this week he had also failed an out-of-competition collection on June 28, 2016.

Lesnar, who is also a WWE superstar, beat Hunt via unanimous decision in Las Vegas on July 9 to claim a record $2.5 million purse.

Hunt referred to Lesnar as a “f***ing cheat” following revelations of his first positive test and demanded the 39-year-old payback his purse.

The UFC and USADA will reportedly not name the drug in question unless Lesnar first does so himself.

The UFC said it had received correspondence from the U.S. Anti-Doping Agency (USADA) and will follow due process in collecting all the facts.   

“The UFC organisation was notified today that the U.S. Anti-Doping Agency (USADA) has informed Brock Lesnar that his in-competition sample collection from July 9, 2016, at UFC 200, has tested positive for the same substance as his previously announced out-of-competition collection on June 28, 2016,” the UFC said in a statement.  

“USADA, the independent administrator of the UFC Anti-Doping Policy, will handle the results management and appropriate adjudication of this case.

“It is important to note that, under the UFC Anti-Doping Policy, there is a full fair legal review process that is afforded to all athletes before any sanctions are imposed.

“The Nevada State Athletic Commission also retains jurisdiction over this matter as the sample collection was performed at UFC 200 in Las Vegas.

“Consistent with all previous potential anti-doping violations, additional information will be provided at the appropriate time as the process moves forward.”

Lesnar’s only response to the positive tests has been “We will get to the bottom of this.”